diff --git a/.changeset/771-agent-named-colors.md b/.changeset/771-agent-named-colors.md
new file mode 100644
index 000000000..6b8594ea5
--- /dev/null
+++ b/.changeset/771-agent-named-colors.md
@@ -0,0 +1,5 @@
+---
+type: Changed
+pr: 823
+---
+Agent `color:` frontmatter now uses Claude Code's documented named colors (`red`/`blue`/`green`/`yellow`/`purple`/`orange`/`pink`/`cyan`) instead of hex values or the undocumented `magenta`, so the intended per-agent TUI color differentiation renders reliably across the Claude Code runtime. Display-only metadata; no behavior change. (#771)
\ No newline at end of file
diff --git a/agents/gsd-ai-researcher.md b/agents/gsd-ai-researcher.md
index 341a5b153..3d1c58ea8 100644
--- a/agents/gsd-ai-researcher.md
+++ b/agents/gsd-ai-researcher.md
@@ -2,7 +2,7 @@
 name: gsd-ai-researcher
 description: Researches a chosen AI framework's official docs to produce implementation-ready guidance — best practices, syntax, core patterns, and pitfalls distilled for the specific use case. Writes the Framework Quick Reference and Implementation Guidance sections of AI-SPEC.md. Spawned by /gsd:ai-integration-phase orchestrator.
 tools: Read, Write, Edit, Bash, Grep, Glob, WebFetch, WebSearch, mcp__context7__*
-color: "#34D399"
+color: green
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-code-fixer.md b/agents/gsd-code-fixer.md
index f7e04266b..841e8b435 100644
--- a/agents/gsd-code-fixer.md
+++ b/agents/gsd-code-fixer.md
@@ -2,7 +2,7 @@
 name: gsd-code-fixer
 description: Applies fixes to code review findings from REVIEW.md. Reads source files, applies intelligent fixes, and commits each fix atomically. Spawned by /gsd:code-review --fix.
 tools: Read, Edit, Write, Bash, Grep, Glob
-color: "#10B981"
+color: green
 # hooks:
 #   - before_write
 ---
diff --git a/agents/gsd-code-reviewer.md b/agents/gsd-code-reviewer.md
index 17a01abec..772c22aeb 100644
--- a/agents/gsd-code-reviewer.md
+++ b/agents/gsd-code-reviewer.md
@@ -2,7 +2,7 @@
 name: gsd-code-reviewer
 description: Reviews source files for bugs, security issues, and code quality problems. Produces structured REVIEW.md with severity-classified findings. Spawned by /gsd:code-review.
 tools: Read, Write, Bash, Grep, Glob
-color: "#F59E0B"
+color: orange
 # hooks:
 #   - before_write
 ---
diff --git a/agents/gsd-domain-researcher.md b/agents/gsd-domain-researcher.md
index 18ba806df..8b55f686d 100644
--- a/agents/gsd-domain-researcher.md
+++ b/agents/gsd-domain-researcher.md
@@ -2,7 +2,7 @@
 name: gsd-domain-researcher
 description: Researches the business domain and real-world application context of the AI system being built. Surfaces domain expert evaluation criteria, industry-specific failure modes, regulatory context, and what "good" looks like for practitioners in this field — before the eval-planner turns it into measurable rubrics. Spawned by /gsd:ai-integration-phase orchestrator.
 tools: Read, Write, Edit, Bash, Grep, Glob, WebSearch, WebFetch, mcp__context7__*
-color: "#A78BFA"
+color: purple
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-eval-auditor.md b/agents/gsd-eval-auditor.md
index d23a6c838..d55503831 100644
--- a/agents/gsd-eval-auditor.md
+++ b/agents/gsd-eval-auditor.md
@@ -2,7 +2,7 @@
 name: gsd-eval-auditor
 description: Retroactive audit of an implemented AI phase's evaluation coverage. Checks implementation against the AI-SPEC.md evaluation plan. Scores each eval dimension as COVERED/PARTIAL/MISSING. Produces a scored EVAL-REVIEW.md with findings, gaps, and remediation guidance. Spawned by /gsd:eval-review orchestrator.
 tools: Read, Write, Bash, Grep, Glob
-color: "#EF4444"
+color: red
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-eval-planner.md b/agents/gsd-eval-planner.md
index 25f61b4b6..5bad98c4a 100644
--- a/agents/gsd-eval-planner.md
+++ b/agents/gsd-eval-planner.md
@@ -2,7 +2,7 @@
 name: gsd-eval-planner
 description: Designs a structured evaluation strategy for an AI phase. Identifies critical failure modes, selects eval dimensions with rubrics, recommends tooling, and specifies the reference dataset. Writes the Evaluation Strategy, Guardrails, and Production Monitoring sections of AI-SPEC.md. Spawned by /gsd:ai-integration-phase orchestrator.
 tools: Read, Write, Edit, Bash, Grep, Glob, AskUserQuestion
-color: "#F59E0B"
+color: orange
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-framework-selector.md b/agents/gsd-framework-selector.md
index c14a4fc02..b9c9d5d99 100644
--- a/agents/gsd-framework-selector.md
+++ b/agents/gsd-framework-selector.md
@@ -2,7 +2,7 @@
 name: gsd-framework-selector
 description: Presents an interactive decision matrix to surface the right AI/LLM framework for the user's specific use case. Produces a scored recommendation with rationale. Spawned by /gsd:ai-integration-phase and /gsd-select-framework orchestrators.
 tools: Read, Bash, Grep, Glob, WebSearch, AskUserQuestion
-color: "#38BDF8"
+color: cyan
 ---
 
 <role>
diff --git a/agents/gsd-nyquist-auditor.md b/agents/gsd-nyquist-auditor.md
index 86d5352a3..35279b10b 100644
--- a/agents/gsd-nyquist-auditor.md
+++ b/agents/gsd-nyquist-auditor.md
@@ -8,7 +8,7 @@ tools:
   - Bash
   - Glob
   - Grep
-color: "#8B5CF6"
+color: purple
 ---
 
 <role>
diff --git a/agents/gsd-pattern-mapper.md b/agents/gsd-pattern-mapper.md
index 9b83144f2..c07288049 100644
--- a/agents/gsd-pattern-mapper.md
+++ b/agents/gsd-pattern-mapper.md
@@ -2,7 +2,7 @@
 name: gsd-pattern-mapper
 description: Analyzes codebase for existing patterns and produces PATTERNS.md mapping new files to closest analogs. Read-only codebase analysis spawned by /gsd:plan-phase orchestrator before planning.
 tools: Read, Bash, Glob, Grep, Write
-color: magenta
+color: purple
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-security-auditor.md b/agents/gsd-security-auditor.md
index 31847360f..209ce4683 100644
--- a/agents/gsd-security-auditor.md
+++ b/agents/gsd-security-auditor.md
@@ -8,7 +8,7 @@ tools:
   - Bash
   - Glob
   - Grep
-color: "#EF4444"
+color: red
 ---
 
 <role>
diff --git a/agents/gsd-ui-auditor.md b/agents/gsd-ui-auditor.md
index 2fd1b1153..3ed6cc9e6 100644
--- a/agents/gsd-ui-auditor.md
+++ b/agents/gsd-ui-auditor.md
@@ -2,7 +2,7 @@
 name: gsd-ui-auditor
 description: Retroactive 6-pillar visual audit of implemented frontend code. Produces scored UI-REVIEW.md. Spawned by /gsd:ui-review orchestrator.
 tools: Read, Write, Bash, Grep, Glob
-color: "#F472B6"
+color: pink
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-ui-checker.md b/agents/gsd-ui-checker.md
index 2ed509e78..adb0e67a3 100644
--- a/agents/gsd-ui-checker.md
+++ b/agents/gsd-ui-checker.md
@@ -2,7 +2,7 @@
 name: gsd-ui-checker
 description: Validates UI-SPEC.md design contracts against 6 quality dimensions. Produces BLOCK/FLAG/PASS verdicts. Spawned by /gsd:ui-phase orchestrator.
 tools: Read, Bash, Glob, Grep
-color: "#22D3EE"
+color: cyan
 ---
 
 <role>
diff --git a/agents/gsd-ui-researcher.md b/agents/gsd-ui-researcher.md
index 3d6ae384d..63a7d6f84 100644
--- a/agents/gsd-ui-researcher.md
+++ b/agents/gsd-ui-researcher.md
@@ -2,7 +2,7 @@
 name: gsd-ui-researcher
 description: Produces UI-SPEC.md design contract for frontend phases. Reads upstream artifacts, detects design system state, asks only unanswered questions. Spawned by /gsd:ui-phase orchestrator.
 tools: Read, Write, Edit, Bash, Grep, Glob, WebSearch, WebFetch, mcp__context7__*, mcp__firecrawl__*, mcp__exa__*, mcp__tavily__*, mcp__ref__*, mcp__jina__*
-color: "#E879F9"
+color: purple
 # hooks:
 #   PostToolUse:
 #     - matcher: "Write|Edit"
diff --git a/agents/gsd-user-profiler.md b/agents/gsd-user-profiler.md
index 6e427fe94..82188804f 100644
--- a/agents/gsd-user-profiler.md
+++ b/agents/gsd-user-profiler.md
@@ -2,7 +2,7 @@
 name: gsd-user-profiler
 description: Analyzes extracted session messages across 8 behavioral dimensions to produce a scored developer profile with confidence levels and evidence. Spawned by profile orchestration workflows.
 tools: Read
-color: magenta
+color: purple
 ---
 
 <role>
diff --git a/docs/AGENTS.md b/docs/AGENTS.md
index ff048bda2..85d0fae12 100644
--- a/docs/AGENTS.md
+++ b/docs/AGENTS.md
@@ -42,6 +42,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | 4 instances (stack, features, architecture, pitfalls) |
 | **Tools** | Read, Write, Bash, Grep, Glob, WebSearch, WebFetch, mcp (context7) |
 | **Model (balanced)** | Sonnet |
+| **Color** | Cyan |
 | **Produces** | `.planning/research/STACK.md`, `FEATURES.md`, `ARCHITECTURE.md`, `PITFALLS.md` |
 
 **Capabilities:**
@@ -61,6 +62,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | 4 instances (same focus areas as project researcher) |
 | **Tools** | Read, Write, Bash, Grep, Glob, WebSearch, WebFetch, mcp (context7) |
 | **Model (balanced)** | Sonnet |
+| **Color** | Cyan |
 | **Produces** | `{phase}-RESEARCH.md` |
 
 **Capabilities:**
@@ -80,7 +82,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Bash, Grep, Glob, WebSearch, WebFetch, mcp (context7) |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#E879F9` (fuchsia) |
+| **Color** | Purple |
 | **Produces** | `{phase}-UI-SPEC.md` |
 
 **Capabilities:**
@@ -268,7 +270,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | Single instance |
 | **Tools** | Read, Bash, Glob, Grep |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#22D3EE` (cyan) |
+| **Color** | Cyan |
 | **Produces** | BLOCK/FLAG/PASS verdict |
 
 ---
@@ -306,6 +308,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Edit, Bash, Grep, Glob |
 | **Model (balanced)** | Sonnet |
+| **Color** | Purple |
 | **Produces** | Test files, updated `VALIDATION.md` |
 
 **Key behaviors:**
@@ -325,7 +328,7 @@ GSD uses a multi-agent architecture where thin orchestrators (workflow files) sp
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Bash, Grep, Glob |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#F472B6` (pink) |
+| **Color** | Pink |
 | **Produces** | `{phase}-UI-REVIEW.md` with scores |
 
 **6 Audit Pillars (scored 1-4):**
@@ -401,7 +404,7 @@ runs its default whole-repo scan.
 | **Parallelism** | Single instance |
 | **Tools** | Read |
 | **Model (balanced)** | Sonnet |
-| **Color** | Magenta |
+| **Color** | Purple |
 | **Produces** | `USER-PROFILE.md`, `CLAUDE.md` profile section |
 
 **Behavioral Dimensions:**
@@ -467,7 +470,7 @@ Communication style, decision patterns, debugging approach, UX preferences, vend
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Edit, Bash, Glob, Grep |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#EF4444` (red) |
+| **Color** | Red |
 | **Produces** | `{phase}-SECURITY.md` |
 
 **Key behaviors:**
@@ -493,7 +496,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance |
 | **Tools** | Read, Bash, Glob, Grep, Write |
 | **Model (balanced)** | Sonnet |
-| **Color** | Magenta |
+| **Color** | Purple |
 | **Produces** | `PATTERNS.md` in the phase directory |
 
 **Key behaviors:**
@@ -533,7 +536,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Typically single instance per review scope |
 | **Tools** | Read, Write, Bash, Grep, Glob |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#F59E0B` (amber) |
+| **Color** | Orange |
 | **Produces** | `REVIEW.md` in the phase directory |
 
 **Key behaviors:**
@@ -553,7 +556,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance |
 | **Tools** | Read, Edit, Write, Bash, Grep, Glob |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#10B981` (emerald) |
+| **Color** | Green |
 | **Produces** | `REVIEW-FIX.md`; one atomic git commit per applied fix |
 
 **Key behaviors:**
@@ -573,7 +576,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance (sequential with domain-researcher / eval-planner) |
 | **Tools** | Read, Write, Bash, Grep, Glob, WebFetch, WebSearch, mcp (context7) |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#34D399` (green) |
+| **Color** | Green |
 | **Produces** | Sections 3–4b of `AI-SPEC.md` (framework quick reference + implementation guidance) |
 
 **Key behaviors:**
@@ -592,7 +595,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Bash, Grep, Glob, WebSearch, WebFetch, mcp (context7) |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#A78BFA` (violet) |
+| **Color** | Purple |
 | **Produces** | Section 1b of `AI-SPEC.md` |
 
 **Key behaviors:**
@@ -611,7 +614,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance (sequential after domain-researcher) |
 | **Tools** | Read, Write, Bash, Grep, Glob, AskUserQuestion |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#F59E0B` (amber) |
+| **Color** | Orange |
 | **Produces** | Sections 5–7 of `AI-SPEC.md` (Evaluation Strategy, Guardrails, Production Monitoring) |
 
 **Required reading:** `gsd-core/references/ai-evals.md` (evaluation framework).
@@ -632,7 +635,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance |
 | **Tools** | Read, Write, Bash, Grep, Glob |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#EF4444` (red) |
+| **Color** | Red |
 | **Produces** | `EVAL-REVIEW.md` with dimension scores, findings, and remediation guidance |
 
 **Required reading:** `gsd-core/references/ai-evals.md`.
@@ -653,7 +656,7 @@ Twelve additional agents ship under `agents/gsd-*.md` and are used by specialty
 | **Parallelism** | Single instance (interactive) |
 | **Tools** | Read, Bash, Grep, Glob, WebSearch, AskUserQuestion |
 | **Model (balanced)** | Sonnet |
-| **Color** | `#38BDF8` (sky blue) |
+| **Color** | Cyan |
 | **Produces** | Scored ranked recommendation (structured return to orchestrator) |
 
 **Required reading:** `gsd-core/references/ai-frameworks.md` (decision matrix).
diff --git a/scripts/research-profiles.cjs b/scripts/research-profiles.cjs
index 58b8ad2b4..01b0c0e7f 100644
--- a/scripts/research-profiles.cjs
+++ b/scripts/research-profiles.cjs
@@ -82,7 +82,7 @@ const PROFILES = [
     name: 'gsd-ai-researcher',
     description:
       'Researches a chosen AI framework\'s official docs to produce implementation-ready guidance — best practices, syntax, core patterns, and pitfalls distilled for the specific use case. Writes the Framework Quick Reference and Implementation Guidance sections of AI-SPEC.md. Spawned by /gsd:ai-integration-phase orchestrator.',
-    color: '"#34D399"',
+    color: 'green',
     tools:
       'Read, Write, Edit, Bash, Grep, Glob, WebFetch, WebSearch, mcp__context7__*',
     requiredIncludes: [
@@ -99,7 +99,7 @@ const PROFILES = [
     name: 'gsd-domain-researcher',
     description:
       'Researches the business domain and real-world application context of the AI system being built. Surfaces domain expert evaluation criteria, industry-specific failure modes, regulatory context, and what "good" looks like for practitioners in this field — before the eval-planner turns it into measurable rubrics. Spawned by /gsd:ai-integration-phase orchestrator.',
-    color: '"#A78BFA"',
+    color: 'purple',
     tools:
       'Read, Write, Edit, Bash, Grep, Glob, WebSearch, WebFetch, mcp__context7__*',
     requiredIncludes: [
@@ -115,7 +115,7 @@ const PROFILES = [
     name: 'gsd-ui-researcher',
     description:
       'Produces UI-SPEC.md design contract for frontend phases. Reads upstream artifacts, detects design system state, asks only unanswered questions. Spawned by /gsd:ui-phase orchestrator.',
-    color: '"#E879F9"',
+    color: 'purple',
     tools:
       'Read, Write, Edit, Bash, Grep, Glob, WebSearch, WebFetch, mcp__context7__*, mcp__firecrawl__*, mcp__exa__*, mcp__tavily__*, mcp__ref__*, mcp__jina__*',
     requiredIncludes: [
diff --git a/tests/agent-frontmatter.test.cjs b/tests/agent-frontmatter.test.cjs
index 5a2b8f4ed..f39ab5155 100644
--- a/tests/agent-frontmatter.test.cjs
+++ b/tests/agent-frontmatter.test.cjs
@@ -232,6 +232,29 @@ describe('AGENT: required frontmatter fields', () => {
   }
 });
 
+// ─── Color Value Validation ──────────────────────────────────────────────────
+
+const VALID_AGENT_COLORS = new Set(['red', 'blue', 'green', 'yellow', 'purple', 'orange', 'pink', 'cyan']);
+
+describe('COLOR: color frontmatter must be a documented named color', () => {
+  for (const agent of ALL_AGENTS) {
+    test(`${agent} color: is a documented named color`, () => {
+      const content = fs.readFileSync(path.join(AGENTS_DIR, agent + '.md'), 'utf-8');
+      const fmMatch = content.match(/^---\r?\n([\s\S]*?)\r?\n---/);
+      const frontmatter = fmMatch ? fmMatch[1] : '';
+      const colorMatch = frontmatter.match(/^color:\s*(.+)$/m);
+      assert.ok(colorMatch, `${agent} missing color: field in frontmatter`);
+      const rawValue = colorMatch[1].trim();
+      // Strip surrounding quotes (single or double) before validating
+      const colorValue = rawValue.replace(/^["']|["']$/g, '');
+      assert.ok(
+        VALID_AGENT_COLORS.has(colorValue),
+        `${agent} has invalid color: "${colorValue}" — must be one of: ${[...VALID_AGENT_COLORS].join(', ')}`
+      );
+    });
+  }
+});
+
 // ─── CLAUDE.md Compliance ───────────────────────────────────────────────────
 
 describe('CLAUDEMD: CLAUDE.md compliance enforcement', () => {