#21bef2 as text	Ratio	AA	AA large	AAA	Fix
Aaon white	2.16:1	fail	fail	fail	AA: use #0a7da4 as the text (4.68:1) AAA: use #07607d as the text (7.05:1) AA: or shift the background to #424242 (4.65:1) AAA: or shift the background to #242424 (7.18:1)
Aaon black	9.71:1	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 #21bef2 as the background.

Brands using this color

Palettes built around it

38bdf8 818cf8 fbbf24 0f172a e2e8f0

Blueprint

Open in tool →

Cyan and indigo on navy is the developer-tool look; amber is the only warm note, so it always reads as 'attention'.

Technical Cool Modern Dark

Fonts for this mood

#21bef2 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

Technical fonts →Modern fonts →

mcpConnect your agent — build around #21bef2

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 #21bef2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21bef2-9cb5c4-df4e70-1f242d-e9f1ef?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