#ef3444 as text	Ratio	AA	AA large	AAA	Fix
Aaon white	4:1	fail	pass	fail	AA: use #e71324 as the text (4.65:1) AAA: use #af0e1c as the text (7.24:1) AA: or shift the background to #141414 (4.6:1)
Aaon black	5.24:1	pass	pass	fail	AAA: use #f36874 as the text (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #ef3444 as the background.

Brands using this color

Wiseprimary · #f4243b · Δ1.507

Palettes built around it

e63946 457b9d f4a261 fff4e0 23201c

Retro Pop

Open in tool →

Fifties-diner red and steel blue with a peach — nostalgic pop that still passes contrast.

Playful Bold Warm

Fonts for this mood

#ef3444 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 #ef3444

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 #ef3444 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/ef3444-c49e9c-62cb8f-2d241f-f1e9ee?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