Color

#155aef

#155aef
hex#155aef
rgbrgb(21, 90, 239)
hslhsl(221, 87%, 51%)
oklchoklch(0.529 0.233 262.7)
Closest name: Blue Ribbon (#0066ff)Relative luminance 0.137

Colors that go with #155aef

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 →

#efaa15

#15c7ef · #3d15ef

#ef155a · #5aef15

Split-complementary

Open in tool →

#ef3d15 · #c7ef15

#ef15c7 · #efaa15 · #15ef3d

Contrast

#155aef as textRatioAAAA largeAAAFix
Aaon white
5.61:1passpassfail
  • AAA: use #0f4cd2 as the text (7.04:1)
Aaon black
3.74:1failpassfail
  • AA: use #326ef1 as the text (4.64:1)
  • AAA: use #6693f4 as the text (7.04:1)
  • AA: or shift the background to #e8e8e8 (4.58:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #155aef as the background.

Brands using this color

Fonts for this mood

#155aef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #155aef
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 #155aef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/155aef-9ca4c4-df6b4e-211f2d-e9eff1?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