Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21871c as the background.

Brands using this color

Instacartsecondary · #108910 · Δ1.164

mcpConnect your agent — build around #21871c

live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp

claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp

try this prompt

›analyze #21871c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21871c-a2bea4-924edf-1f2d25-edf1e9?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md