Color

#181731

#181731
hex#181731
rgbrgb(24, 23, 49)
hslhsl(242, 36%, 14%)
oklchoklch(0.221 0.05 283.3)
Closest name: Dark Knight (#151931)Relative luminance 0.0103

Colors that go with #181731

Charcoal, Dark Olive Green and Sea Green 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.

Real palettes that use #181731

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#303117

#172331 · #251731

#311817 · #173118

Split-complementary

Open in tool →

#312517 · #233117

#311723 · #303117 · #173125

Contrast

#181731 as textRatioAAAA largeAAAFix
Aaon white
17.42:1passpasspassPasses AAA — no fix needed.
Aaon black
1.21:1failfailfail
  • AA: use #706dba as the text (4.59:1)
  • AAA: use #9290cb as the text (7.07:1)
  • AA: or shift the background to #828282 (4.53:1)
  • AAA: or shift the background to #a6a6a6 (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #181731 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#181731 reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #181731
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 #181731 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/181731-a29cc4-df9e4e-261f2d-e9edf1?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