MCP Color Server

Instructions

Implementation Reference

• src/tools/index.ts:130-130 (registration)

  Registers the generateThemeTool in the central ToolRegistry singleton instance.
  toolRegistry.registerTool(generateThemeTool);
• src/tools/generate-theme.ts:11-36 (schema)

  TypeScript interface defining the input parameters (GenerateThemeParams) for the generate_theme tool.
  export interface GenerateThemeParams { theme_type: | 'light' | 'dark' | 'auto' | 'high_contrast' | 'colorblind_friendly'; primary_color: string; style?: 'material' | 'ios' | 'fluent' | 'custom'; components?: Array< | 'background' | 'surface' | 'primary' | 'secondary' | 'accent' | 'text' | 'border' | 'shadow' | 'success' | 'warning' | 'error' | 'info' >; accessibility_level?: 'AA' | 'AAA'; brand_colors?: string[]; }
• src/tools/generate-theme.ts:64-90 (schema)

  TypeScript interface defining the detailed response structure (GenerateThemeResponse) returned by the generate_theme tool.
  export interface GenerateThemeResponse { theme_type: string; style: string; primary_color: string; variants: { light?: ThemeVariant; dark?: ThemeVariant; }; accessibility_report: { overall_score: number; wcag_compliance: 'AA' | 'AAA' | 'FAIL'; contrast_issues: Array<{ combination: [string, string]; contrast_ratio: number; required_ratio: number; passes: boolean; }>; recommendations: string[]; }; brand_integration?: | { brand_colors_used: string[]; harmony_maintained: boolean; adjustments_made: string[]; } | undefined; }
• src/tools/generate-theme.ts:898-960 (schema)

  The complete tool definition object including MCP JSON schema (parameters), description, and handler wrapper that delegates to the main generateTheme function.
  // Tool definition for MCP registration export const generateThemeTool = { name: 'generate_theme', description: 'Generate complete design system themes with semantic color mapping', parameters: { type: 'object', properties: { theme_type: { type: 'string', enum: ['light', 'dark', 'auto', 'high_contrast', 'colorblind_friendly'], description: 'Type of theme to generate', }, primary_color: { type: 'string', description: 'Primary brand color for the theme', }, style: { type: 'string', enum: ['material', 'ios', 'fluent', 'custom'], description: 'Design system style', default: 'material', }, components: { type: 'array', items: { type: 'string', enum: [ 'background', 'surface', 'primary', 'secondary', 'accent', 'text', 'border', 'shadow', 'success', 'warning', 'error', 'info', ], }, description: 'Components to generate colors for', }, accessibility_level: { type: 'string', enum: ['AA', 'AAA'], description: 'WCAG accessibility level to target', default: 'AA', }, brand_colors: { type: 'array', items: { type: 'string', }, description: 'Additional brand colors to incorporate', }, }, required: ['theme_type', 'primary_color'], }, handler: async (params: unknown) => generateTheme(params as GenerateThemeParams), };
• src/tools/generate-theme.ts:95-325 (handler)

  Core handler function that performs input validation, generates theme variants (light/dark/high-contrast/colorblind), computes accessibility reports, integrates brand colors, and constructs the final tool response.
  export async function generateTheme( params: GenerateThemeParams ): Promise<ToolResponse | ErrorResponse> { const startTime = Date.now(); try { // Validate required parameters if (!params.primary_color) { return createErrorResponse( 'generate_theme', 'MISSING_PARAMETER', 'Primary color parameter is required', Date.now() - startTime, { details: { parameter: 'primary_color' }, suggestions: ['Provide a primary color in any supported format'], } ); } if (!params.theme_type) { return createErrorResponse( 'generate_theme', 'MISSING_PARAMETER', 'Theme type parameter is required', Date.now() - startTime, { details: { parameter: 'theme_type' }, suggestions: [ 'Specify theme type: light, dark, auto, high_contrast, or colorblind_friendly', ], } ); } // Validate primary color const primaryValidation = validateColorInput(params.primary_color); if (!primaryValidation.isValid) { return createErrorResponse( 'generate_theme', 'INVALID_PRIMARY_COLOR', `Invalid primary color format: ${params.primary_color}`, Date.now() - startTime, { details: { provided: params.primary_color, error: primaryValidation.error, }, suggestions: [ 'Use a valid color format like #2563eb or rgb(37, 99, 235)', ], } ); } // Validate brand colors if provided const brandColors: UnifiedColor[] = []; if (params.brand_colors) { for (const brandColor of params.brand_colors) { const validation = validateColorInput(brandColor); if (!validation.isValid) { return createErrorResponse( 'generate_theme', 'INVALID_BRAND_COLOR', `Invalid brand color format: ${brandColor}`, Date.now() - startTime, { details: { provided: brandColor, error: validation.error }, suggestions: ['Ensure all brand colors are in valid formats'], } ); } brandColors.push(new UnifiedColor(brandColor)); } } // Parse primary color const primaryColor = new UnifiedColor(params.primary_color); // Set defaults const style = params.style || 'material'; const accessibilityLevel = params.accessibility_level || 'AA'; const components = params.components || [ 'background', 'surface', 'primary', 'secondary', 'accent', 'text', 'border', 'shadow', 'success', 'warning', 'error', 'info', ]; // Generate theme variants const variants: { light?: ThemeVariant; dark?: ThemeVariant } = {}; if (params.theme_type === 'light' || params.theme_type === 'auto') { variants.light = await generateLightTheme( primaryColor, style, accessibilityLevel, components, brandColors ); } if (params.theme_type === 'dark' || params.theme_type === 'auto') { variants.dark = await generateDarkTheme( primaryColor, style, accessibilityLevel, components, brandColors ); } if (params.theme_type === 'high_contrast') { variants.light = await generateHighContrastTheme( primaryColor, 'light', accessibilityLevel, components, brandColors ); variants.dark = await generateHighContrastTheme( primaryColor, 'dark', accessibilityLevel, components, brandColors ); } if (params.theme_type === 'colorblind_friendly') { variants.light = await generateColorblindFriendlyTheme( primaryColor, 'light', accessibilityLevel, components, brandColors ); variants.dark = await generateColorblindFriendlyTheme( primaryColor, 'dark', accessibilityLevel, components, brandColors ); } // Generate accessibility report const accessibilityReport = await generateAccessibilityReport( variants, accessibilityLevel ); // Generate brand integration report const brandIntegration = brandColors.length > 0 ? await generateBrandIntegrationReport(brandColors, variants) : undefined; // Prepare response const responseData: GenerateThemeResponse = { theme_type: params.theme_type, style, primary_color: params.primary_color, variants, accessibility_report: accessibilityReport, brand_integration: brandIntegration, }; const executionTime = Date.now() - startTime; // Generate accessibility notes const accessibilityNotes: string[] = []; if (accessibilityReport.wcag_compliance === 'FAIL') { accessibilityNotes.push('Theme does not meet minimum WCAG standards'); } else if (accessibilityReport.wcag_compliance === 'AA') { accessibilityNotes.push('Theme meets WCAG AA accessibility standards'); } else { accessibilityNotes.push('Theme meets WCAG AAA accessibility standards'); } const recommendations: string[] = []; if (accessibilityReport.contrast_issues.length > 0) { recommendations.push( `${accessibilityReport.contrast_issues.length} contrast issues found - see accessibility report` ); } if (brandIntegration && !brandIntegration.harmony_maintained) { recommendations.push('Brand color harmony could be improved'); } return createSuccessResponse( 'generate_theme', responseData, executionTime, { colorSpaceUsed: 'sRGB', accessibilityNotes, recommendations: recommendations .concat(accessibilityReport.recommendations) .slice(0, 5), } ); } catch (error) { const executionTime = Date.now() - startTime; return createErrorResponse( 'generate_theme', 'THEME_GENERATION_ERROR', `Failed to generate theme: ${error instanceof Error ? error.message : 'Unknown error'}`, executionTime, { details: { theme_type: params.theme_type, primary_color: params.primary_color, }, suggestions: [ 'Check that the primary color is in a valid format', 'Ensure theme type is supported', 'Try with different parameters', ], } ); } }