Color

#1b81bb

#1b81bb
hex#1b81bb
rgbrgb(27, 129, 187)
hslhsl(202, 75%, 42%)
oklchoklch(0.576 0.124 240.5)
Closest name: Haddock’s Sweater (#277aba)Relative luminance 0.1952

Colors that go with #1b81bb

Charcoal, Crimson and Copper 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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#bb561b

#1bbba6 · #1b30bb

#bb1b81 · #81bb1b

Split-complementary

Open in tool →

#bb1b30 · #bba61b

#a61bbb · #bb561b · #30bb1b

Contrast

#1b81bb as textRatioAAAA largeAAAFix
Aaon white
4.28:1failpassfail
  • AA: use #1a7db7 as the text (4.51:1)
  • AAA: use #135c86 as the text (7.23:1)
  • AA: or shift the background to #0d0d0d (4.54:1)
Aaon black
4.9:1passpassfail
  • AAA: use #2d9fe1 as the text (7.16:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b81bb as the background.

Brands using this color

Fonts for this mood

#1b81bb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b81bb
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 #1b81bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b81bb-9cb1c4-df4e5f-1f222d-e9f1f0?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