Color

#1b83bb

#1b83bb
hex#1b83bb
rgbrgb(27, 131, 187)
hslhsl(201, 75%, 42%)
oklchoklch(0.581 0.123 239.1)
Closest name: Haddock’s Sweater (#277aba)Relative luminance 0.2005

Colors that go with #1b83bb

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 →

#bb531b

#1bbba3 · #1b33bb

#bb1b83 · #83bb1b

Split-complementary

Open in tool →

#bb1b33 · #bba31b

#a31bbb · #bb531b · #33bb1b

Contrast

#1b83bb as textRatioAAAA largeAAAFix
Aaon white
4.19:1failpassfail
  • AA: use #197db3 as the text (4.54:1)
  • AAA: use #135e86 as the text (7.06:1)
  • AA: or shift the background to #0f0f0f (4.57:1)
Aaon black
5.01:1passpassfail
  • AAA: use #249ee0 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 #1b83bb as the background.

Brands using this color

Fonts for this mood

#1b83bb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b83bb
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 #1b83bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b83bb-9cb1c4-df4e62-1f222d-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