Color

#183a54

#183a54
hex#183a54
rgbrgb(24, 58, 84)
hslhsl(206, 56%, 21%)
oklchoklch(0.336 0.061 244.2)
Closest name: Maniac Mansion (#004058)Relative luminance 0.0386

Colors that go with #183a54

Royal Blue, Teal 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 →

#543218

#185450 · #181c54

#54183a · #3a5418

Split-complementary

Open in tool →

#54181c · #545018

#501854 · #543218 · #1c5418

Contrast

#183a54 as textRatioAAAA largeAAAFix
Aaon white
11.85:1passpasspassPasses AAA — no fix needed.
Aaon black
1.77:1failfailfail
  • AA: use #327bb3 as the text (4.62:1)
  • AAA: use #589cd0 as the text (7.08:1)
  • AA: or shift the background to #a1a1a1 (4.59:1)
  • AAA: or shift the background to #c7c7c7 (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183a54 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#183a54 reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183a54
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 #183a54 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183a54-9caec4-df4e56-1f212d-e9f1f1?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