Color

#3b91ab

#3b91ab
hex#3b91ab
rgbrgb(59, 145, 171)
hslhsl(194, 49%, 45%)
oklchoklch(0.615 0.09 221.2)
Closest name: Blue Moon (#3992a8)Relative luminance 0.2412

Colors that go with #3b91ab

Charcoal, Copper and Crimson lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.

Real palettes that use #3b91ab

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#ab553b

#3bab8d · #3b59ab

#ab3b91 · #91ab3b

Split-complementary

Open in tool →

#ab3b59 · #ab8d3b

#8d3bab · #ab553b · #59ab3b

Contrast

#3b91ab as textRatioAAAA largeAAAFix
Aaon white
3.61:1failpassfail
  • AA: use #337d94 as the text (4.66:1)
  • AAA: use #265d6e as the text (7.31:1)
  • AA: or shift the background to #1f1f1f (4.57:1)
Aaon black
5.82:1passpassfail
  • AAA: use #41a1be as the text (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3b91ab as the background.

Brands using this color

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

Fonts for this mood

#3b91ab reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3b91ab
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #3b91ab and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3b91ab-9cb6c4-df4e72-1f242d-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