Generate Brand Color Palettes
Create cohesive color palettes for brand identities, websites, and design systems — from a seed color or a descriptive prompt.
Check Color Accessibility Contrast Ratios
Verify text and background color combinations meet WCAG AA or AAA accessibility standards before shipping to production.
Quick answer: Use the Color Tools tool through ToolRouter to check color accessibility contrast ratios directly from Claude, ChatGPT, Microsoft Copilot, and OpenClaw — connect once, then drive it with plain-language prompts. No code required.
ToolAccessibility failures are silent until someone complains or you fail an audit. The most common accessibility issue on the web is insufficient color contrast — text that technically exists in the design but is unreadable to anyone with low vision, in bright sunlight, or on a lower-quality display.
Color Tools' check_contrast skill calculates the WCAG contrast ratio between any two colors and tells you whether the combination passes AA (the legal minimum for most accessibility requirements), AAA (optimal), or fails completely — with enough specificity to know whether the failure is in normal text, large text, or UI elements.
Designers reviewing designs before developer handoff, developers checking color token implementations, and product managers who need to certify that their application meets accessibility requirements use check_contrast to catch failures before they reach users.
How to check color accessibility contrast ratios with Claude, ChatGPT, Microsoft Copilot, and OpenClaw
Connect ToolRouter
1Open connector settings Open Settings
2Add a custom connector with these details
Name
ToolRouterURL
https://api.toolrouter.com/mcp3Let Claude set you up Open Claude
Claude is the right partner for contrast checking when you need to understand why a combination fails and what alternatives would fix it — not just the pass/fail result but a concrete path to a compliant design.
How to check color accessibility contrast ratios
Once connected (see setup above), use the Color Tools tool — the same steps work with Claude, ChatGPT, Microsoft Copilot, OpenClaw, and any MCP client:
- Provide the foreground and background hex values and describe the use case — body text, large heading, button label, icon.
- Run color-tools with check_contrast for the color pair.
- Ask Claude to explain the failure if it does not pass, and suggest two or three alternative colors that would achieve AA compliance while staying close to the original.
- Update the design with the compliant alternative.
Example prompt
Try this with the Color Tools tool
Use color-tools to check the contrast between our brand blue #2D5BE3 and white #FFFFFF for body text, then between that blue and our background grey #F5F5F5. Does each combination pass WCAG AA? If the grey background fails, suggest the darkest version of our blue that would still pass.
Tips
- Check contrast at all text sizes — WCAG has different requirements for normal text (4.5:1) versus large text (3:1).
- Ask Claude to suggest an alternative that is as close to the original as possible — accessibility fixes do not have to destroy the design.
- Check your most common text-on-background combination first — that is where failures affect the most users.
Frequently Asked Questions
How do I check color accessibility contrast ratios with an AI assistant?
Verify text and background color combinations meet WCAG AA or AAA accessibility standards before shipping to production. Connect the Color Tools tool to Claude, ChatGPT, Microsoft Copilot, and OpenClaw through ToolRouter, then ask the assistant in plain language. For example: Provide the foreground and background hex values and describe the use case — body text, large heading, button label, icon. Run color-tools with check_contrast for the color pair.
Which AI assistants can check color accessibility contrast ratios?
Claude, ChatGPT, Microsoft Copilot, and OpenClaw can all check color accessibility contrast ratios using the Color Tools tool through ToolRouter, with no API keys or coding required.
What does the Color Tools tool do?
Generate color palettes, check accessibility contrast ratios, and get AI-curated color schemes from a prompt.
Related Use Cases
Get Color Information and Names
Look up detailed information about any color — name, hex, RGB, HSL, CMYK values, and complementary colors — for design and development use.