Color

#031b4e

#031b4e
hex#031b4e
rgbrgb(3, 27, 78)
hslhsl(221, 93%, 16%)
oklchoklch(0.243 0.099 261.9)
Closest name: Interstellar Blue (#001155)Relative luminance 0.0135

Colors that go with #031b4e

Blue Violet, Charcoal and Crimson 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 →

#4f3703

#03414f · #11034f

#4f031b · #1b4f03

Split-complementary

Open in tool →

#4f1103 · #414f03

#4f0341 · #4f3703 · #034f11

Contrast

#031b4e as textRatioAAAA largeAAAFix
Aaon white
16.53:1passpasspassPasses AAA — no fix needed.
Aaon black
1.27:1failfailfail
  • AA: use #2b6cf7 as the text (4.59:1)
  • AAA: use #6695f9 as the text (7.23:1)
  • AA: or shift the background to #878787 (4.6:1)
  • AAA: or shift the background to #ababab (7.2:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #031b4e as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#031b4e reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #031b4e
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 #031b4e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/031b4e-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