Color

#183ea0

#183ea0
hex#183ea0
rgbrgb(24, 62, 160)
hslhsl(223, 74%, 36%)
oklchoklch(0.405 0.165 264.1)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0618

Colors that go with #183ea0

Charcoal, Sea Green and Steel 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 →

#a07918

#1882a0 · #3518a0

#a0183e · #3ea018

Split-complementary

Open in tool →

#a03518 · #82a018

#a01882 · #a07918 · #18a035

Contrast

#183ea0 as textRatioAAAA largeAAAFix
Aaon white
9.39:1passpasspassPasses AAA — no fix needed.
Aaon black
2.24:1failfailfail
  • AA: use #406ee2 as the text (4.55:1)
  • AAA: use #7193ea as the text (7.06:1)
  • AA: or shift the background to #b5b5b5 (4.58:1)
  • AAA: or shift the background to #e0e0e0 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183ea0 as the background.

Brands using this color

Fonts for this mood

#183ea0 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183ea0
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 #183ea0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183ea0-9ca3c4-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