Color

#042dfb

#042dfb
hex#042dfb
rgbrgb(4, 45, 251)
hslhsl(230, 97%, 50%)
oklchoklch(0.474 0.291 264.4)
Closest name: C64 Blue (#003aff)Relative luminance 0.0887

Colors that go with #042dfb

Charcoal, Crimson and Cobalt 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 →

#fbd204

#04a9fb · #5604fb

#fb042d · #2dfb04

Split-complementary

Open in tool →

#fb5604 · #a9fb04

#fb04a9 · #fbd204 · #04fb56

Contrast

#042dfb as textRatioAAAA largeAAAFix
Aaon white
7.57:1passpasspassPasses AAA — no fix needed.
Aaon black
2.77:1failfailfail
  • AA: use #4a68fc as the text (4.68:1)
  • AAA: use #778efd as the text (7.07:1)
  • AA: or shift the background to #c9c9c9 (4.57:1)
  • AAA: or shift the background to #f7f7f7 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #042dfb as the background.

Brands using this color

Fonts for this mood

#042dfb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #042dfb
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 #042dfb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/042dfb-9c9ec4-df814e-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