Color

#0243bb

#0243bb
hex#0243bb
rgbrgb(2, 67, 187)
hslhsl(219, 98%, 37%)
oklchoklch(0.436 0.197 261.9)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0762

Colors that go with #0243bb

Charcoal, Crimson and Steel Blue 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 →

#bb7a02

#029fbb · #1e02bb

#bb0243 · #43bb02

Split-complementary

Open in tool →

#bb1e02 · #9fbb02

#bb029f · #bb7a02 · #02bb1e

Contrast

#0243bb as textRatioAAAA largeAAAFix
Aaon white
8.32:1passpasspassPasses AAA — no fix needed.
Aaon black
2.52:1failfailfail
  • AA: use #1c6bfd as the text (4.57:1)
  • AAA: use #5d95fd as the text (7.18:1)
  • AA: or shift the background to #bfbfbf (4.53:1)
  • AAA: or shift the background to #ededed (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0243bb as the background.

Brands using this color

Fonts for this mood

#0243bb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0243bb
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 #0243bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0243bb-9ca5c4-df664e-211f2d-e9f0f1?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