#21de2b as text	Ratio	AA	AA large	AAA	Fix
Aaon white	1.82:1	fail	fail	fail	AA: use #14851a as the text (4.77:1) AAA: use #0f6614 as the text (7.16:1) AA: or shift the background to #4f4f4f (4.5:1) AAA: or shift the background to #303030 (7.26:1)
Aaon black	11.55:1	pass	pass	pass	Passes AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21de2b as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

mcpConnect your agent — build around #21de2b

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 #21de2b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21de2b-a2bea6-a04edf-1f2d26-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