Color

#042d8b

#042d8b
hex#042d8b
rgbrgb(4, 45, 139)
hslhsl(222, 94%, 28%)
oklchoklch(0.346 0.161 262.9)
Closest name: Below the Surface (#0a2f7c)Relative luminance 0.0377

Colors that go with #042d8b

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 →

#8b6204

#04708b · #1f048b

#8b042d · #2d8b04

Split-complementary

Open in tool →

#8b1f04 · #708b04

#8b0470 · #8b6204 · #048b1f

Contrast

#042d8b as textRatioAAAA largeAAAFix
Aaon white
11.98:1passpasspassPasses AAA — no fix needed.
Aaon black
1.75:1failfailfail
  • AA: use #2f6cf9 as the text (4.63:1)
  • AAA: use #6692fa as the text (7.06:1)
  • AA: or shift the background to #a1a1a1 (4.64:1)
  • AAA: or shift the background to #c7c7c7 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #042d8b as the background.

Brands using this color

Fonts for this mood

#042d8b reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #042d8b
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 #042d8b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/042d8b-9ca3c4-df6e4e-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