Color

#183e4e

#183e4e
hex#183e4e
rgbrgb(24, 62, 78)
hslhsl(198, 53%, 20%)
oklchoklch(0.344 0.051 228.6)
Closest name: Cold and Dark (#154250)Relative luminance 0.0419

Colors that go with #183e4e

Crimson, Royal Blue and Teal 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 →

#4e2818

#184e43 · #18234e

#4e183e · #3e4e18

Split-complementary

Open in tool →

#4e1823 · #4e4318

#43184e · #4e2818 · #234e18

Contrast

#183e4e as textRatioAAAA largeAAAFix
Aaon white
11.43:1passpasspassPasses AAA — no fix needed.
Aaon black
1.84:1failfailfail
  • AA: use #317fa0 as the text (4.67:1)
  • AAA: use #449fc5 as the text (7.01:1)
  • AA: or shift the background to #a3a3a3 (4.53:1)
  • AAA: or shift the background to #cccccc (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183e4e as the background.

Brands using this color

Fonts for this mood

#183e4e reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183e4e
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 #183e4e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183e4e-9cb3c4-df4e69-1f232d-e9f1f0?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