Color

#183b8b

#183b8b
hex#183b8b
rgbrgb(24, 59, 139)
hslhsl(222, 71%, 32%)
oklchoklch(0.38 0.14 263.4)
Closest name: Deep Space Royal (#223382)Relative luminance 0.0519

Colors that go with #183b8b

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 →

#8c6918

#18748c · #2f188c

#8c183a · #3a8c18

Split-complementary

Open in tool →

#8c2f18 · #748c18

#8c1874 · #8c6918 · #188c2f

Contrast

#183b8b as textRatioAAAA largeAAAFix
Aaon white
10.31:1passpasspassPasses AAA — no fix needed.
Aaon black
2.04:1failfailfail
  • AA: use #3f6fde as the text (4.54:1)
  • AAA: use #6f93e7 as the text (7:1)
  • AA: or shift the background to #adadad (4.59:1)
  • AAA: or shift the background to #d6d6d6 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183b8b as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#183b8b reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183b8b
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 #183b8b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183b8b-9ca3c4-df6e4e-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