Color

#183a91

#183a91
hex#183a91
rgbrgb(24, 58, 145)
hslhsl(223, 72%, 33%)
oklchoklch(0.383 0.149 264.2)
Closest name: Deep Space Royal (#223382)Relative luminance 0.0526

Colors that go with #183a91

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 →

#916e18

#187691 · #321891

#91183a · #3a9118

Split-complementary

Open in tool →

#913218 · #769118

#911876 · #916e18 · #189132

Contrast

#183a91 as textRatioAAAA largeAAAFix
Aaon white
10.23:1passpasspassPasses AAA — no fix needed.
Aaon black
2.05:1failfailfail
  • AA: use #426fe0 as the text (4.58:1)
  • AAA: use #7394e8 as the text (7.13:1)
  • AA: or shift the background to #adadad (4.56:1)
  • AAA: or shift the background to #d6d6d6 (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 #183a91 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#183a91 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183a91
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 #183a91 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183a91-9ca3c4-df704e-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