Color

#181f6d

#181f6d
hex#181f6d
rgbrgb(24, 31, 109)
hslhsl(235, 64%, 26%)
oklchoklch(0.294 0.133 271.2)
Closest name: midnightblue (#191970)Relative luminance 0.0228

Colors that go with #181f6d

Charcoal, Steel Blue and 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 →

#6d6618

#18496d · #3b186d

#6d181f · #1f6d18

Split-complementary

Open in tool →

#6d3b18 · #496d18

#6d1849 · #6d6618 · #186d3b

Contrast

#181f6d as textRatioAAAA largeAAAFix
Aaon white
14.43:1passpasspassPasses AAA — no fix needed.
Aaon black
1.46:1failfailfail
  • AA: use #606adc as the text (4.59:1)
  • AAA: use #868ee4 as the text (7:1)
  • AA: or shift the background to #919191 (4.58:1)
  • AAA: or shift the background to #b5b5b5 (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #181f6d as the background.

Brands using this color

Fonts for this mood

#181f6d reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #181f6d
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 #181f6d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/181f6d-9e9cc4-df8d4e-241f2d-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