Color

#001b57

#001b57
hex#001b57
rgbrgb(0, 27, 87)
hslhsl(221, 100%, 17%)
oklchoklch(0.252 0.113 261.6)
Closest name: Interstellar Blue (#001155)Relative luminance 0.0147

Colors that go with #001b57

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 →

#573b00

#004757 · #100057

#57001b · #1b5700

Split-complementary

Open in tool →

#571000 · #475700

#570047 · #573b00 · #005710

Contrast

#001b57 as textRatioAAAA largeAAAFix
Aaon white
16.22:1passpasspassPasses AAA — no fix needed.
Aaon black
1.29:1failfailfail
  • AA: use #2469ff as the text (4.54:1)
  • AAA: use #6193ff as the text (7.13:1)
  • AA: or shift the background to #878787 (4.52:1)
  • AAA: or shift the background to #ababab (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #001b57 as the background.

Brands using this color

Fonts for this mood

#001b57 reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #001b57
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 #001b57 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/001b57-9ca4c4-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