Color

#03123f

#03123f
hex#03123f
rgbrgb(3, 18, 63)
hslhsl(225, 91%, 13%)
oklchoklch(0.206 0.089 263.9)
Closest name: Infinite Night (#071037)Relative luminance 0.0081

Colors that go with #03123f

Charcoal, Rust and Sienna 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 →

#3f3003

#03303f · #12033f

#3f0312 · #123f03

Split-complementary

Open in tool →

#3f1203 · #303f03

#3f0330 · #3f3003 · #033f12

Contrast

#03123f as textRatioAAAA largeAAAFix
Aaon white
18.07:1passpasspassPasses AAA — no fix needed.
Aaon black
1.16:1failfailfail
  • AA: use #3c6bf6 as the text (4.63:1)
  • AAA: use #7293f8 as the text (7.24:1)
  • AA: or shift the background to #808080 (4.58:1)
  • AAA: or shift the background to #a3a3a3 (7.16:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #03123f as the background.

Brands using this color

Fonts for this mood

#03123f reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #03123f
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 #03123f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/03123f-9ca1c4-df754e-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