#c21000 as text	Ratio	AA	AA large	AAA	Fix
Aaon white	6.24:1	pass	pass	fail	AAA: use #b30f00 as the text (7.04:1)
Aaon black	3.37:1	fail	pass	fail	AA: use #eb1400 as the text (4.63:1) AAA: use #ff6052 as the text (7.05:1) AA: or shift the background to #dbdbdb (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #c21000 as the background.

Brands using this color

Datadogaccent · #bf0000 · Δ1.106

Fonts for this mood

#c21000 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

Warm fonts →Playful fonts →Bold fonts →

mcpConnect your agent — build around #c21000

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 #c21000 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/c21000-c4a49c-62cba1-2d261f-f1e9ec?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