Color

#183bc9

#183bc9
hex#183bc9
rgbrgb(24, 59, 201)
hslhsl(228, 79%, 44%)
oklchoklch(0.44 0.22 265.6)
Closest name: Lapis on Neptune (#1f22d2)Relative luminance 0.0754

Colors that go with #183bc9

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 →

#c9a518

#1894c9 · #4d18c9

#c9183b · #3bc918

Split-complementary

Open in tool →

#c94d18 · #94c918

#c91894 · #c9a518 · #18c94d

Contrast

#183bc9 as textRatioAAAA largeAAAFix
Aaon white
8.37:1passpasspassPasses AAA — no fix needed.
Aaon black
2.51:1failfailfail
  • AA: use #4d6cea as the text (4.65:1)
  • AAA: use #7b92ef as the text (7.2:1)
  • AA: or shift the background to #bfbfbf (4.55:1)
  • AAA: or shift the background to #ebebeb (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183bc9 as the background.

Brands using this color

Fonts for this mood

#183bc9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183bc9
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 #183bc9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183bc9-9c9fc4-df7c4e-231f2d-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