#309ef3 as text	Ratio	AA	AA large	AAA	Fix
Aaon white	2.87:1	fail	fail	fail	AA: use #0c78ca as the text (4.61:1) AAA: use #095b9a as the text (7.06:1) AA: or shift the background to #303030 (4.59:1) AAA: or shift the background to #050505 (7.1:1)
Aaon black	7.31:1	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 #309ef3 as the background.

Brands using this color

JetBrainssecondary · #18a3fa · Δ1.554

Fonts for this mood

#309ef3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

Technical fonts →Modern fonts →

mcpConnect your agent — build around #309ef3

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 #309ef3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/309ef3-9caec4-df4e56-1f212d-e9f1f1?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