Color

#182121

#182121
hex#182121
rgbrgb(24, 33, 33)
hslhsl(180, 16%, 11%)
oklchoklch(0.239 0.013 196.3)
Closest name: Underworld (#1e231c)Relative luminance 0.0139

Colors that go with #182121

Charcoal, Amber 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 →

#211818

#18211c · #181c21

#211821 · #212118

Split-complementary

Open in tool →

#21181c · #211c18

#1c1821 · #211818 · #1c2118

Contrast

#182121 as textRatioAAAA largeAAAFix
Aaon white
16.43:1passpasspassPasses AAA — no fix needed.
Aaon black
1.28:1failfailfail
  • AA: use #5a7c7c as the text (4.61:1)
  • AAA: use #779c9c as the text (7.02:1)
  • AA: or shift the background to #878787 (4.57:1)
  • AAA: or shift the background to #ababab (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 #182121 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#182121 reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #182121
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 #182121 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/182121-a2bbbe-d45994-1f272d-e9f1ed?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