Color

#183f6d

#183f6d
hex#183f6d
rgbrgb(24, 63, 109)
hslhsl(212, 64%, 26%)
oklchoklch(0.366 0.091 254.5)
Closest name: Aegean Blue (#1b416f)Relative luminance 0.0485

Colors that go with #183f6d

Crimson, Teal 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 →

#6d4518

#186a6d · #1b186d

#6d183f · #3f6d18

Split-complementary

Open in tool →

#6d1b18 · #6a6d18

#6d186a · #6d4518 · #186d1b

Contrast

#183f6d as textRatioAAAA largeAAAFix
Aaon white
10.66:1passpasspassPasses AAA — no fix needed.
Aaon black
1.97:1failfailfail
  • AA: use #2d78cd as the text (4.68:1)
  • AAA: use #609adc as the text (7.15:1)
  • AA: or shift the background to #ababab (4.64:1)
  • AAA: or shift the background to #d4d4d4 (7.19:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183f6d as the background.

Brands using this color

Fonts for this mood

#183f6d reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183f6d
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 #183f6d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183f6d-9caac4-df564e-1f202d-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