Color

#2155e4

#2155e4
hex#2155e4
rgbrgb(33, 85, 228)
hslhsl(224, 78%, 51%)
oklchoklch(0.513 0.223 264.3)
Closest name: Blue Ribbon (#0066ff)Relative luminance 0.1242

Colors that go with #2155e4

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.

Real palettes that use #2155e4

Tints & shades

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

Harmonies

Complementary

Open in tool →

#e4b021

#21b6e4 · #4e21e4

#e42155 · #55e421

Split-complementary

Open in tool →

#e44e21 · #b6e421

#e421b6 · #e4b021 · #21e44e

Contrast

#2155e4 as textRatioAAAA largeAAAFix
Aaon white
6.03:1passpassfail
  • AAA: use #1a4bd1 as the text (7.07:1)
Aaon black
3.48:1failpassfail
  • AA: use #406de7 as the text (4.56:1)
  • AAA: use #7293ee as the text (7.12:1)
  • AA: or shift the background to #e0e0e0 (4.57:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #2155e4 as the background.

Brands using this color

Fonts for this mood

#2155e4 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #2155e4
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 #2155e4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/2155e4-9ca2c4-df724e-221f2d-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