Color

#1b42ee

#1b42ee
hex#1b42ee
rgbrgb(27, 66, 238)
hslhsl(229, 86%, 52%)
oklchoklch(0.49 0.256 265.6)
Closest name: C64 Blue (#003aff)Relative luminance 0.103

Colors that go with #1b42ee

Charcoal, Crimson and Amber 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 →

#eec71b

#1babee · #5e1bee

#ee1b42 · #42ee1b

Split-complementary

Open in tool →

#ee5e1b · #abee1b

#ee1bab · #eec71b · #1bee5e

Contrast

#1b42ee as textRatioAAAA largeAAAFix
Aaon white
6.86:1passpassfail
  • AAA: use #173eee as the text (7.09:1)
Aaon black
3.06:1failpassfail
  • AA: use #4b69f1 as the text (4.59:1)
  • AAA: use #7a91f5 as the text (7.2:1)
  • AA: or shift the background to #d4d4d4 (4.63:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b42ee as the background.

Brands using this color

Fonts for this mood

#1b42ee reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b42ee
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 #1b42ee and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b42ee-9c9fc4-df7e4e-231f2d-e9eef1?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