Color

#183d5d

#183d5d
hex#183d5d
rgbrgb(24, 61, 93)
hslhsl(208, 59%, 23%)
oklchoklch(0.35 0.07 247.5)
Closest name: Capital Blue (#1a4157)Relative luminance 0.0432

Colors that go with #183d5d

Crimson, Teal and Sienna 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 →

#5d3818

#185d5b · #181a5d

#5d183d · #3d5d18

Split-complementary

Open in tool →

#5d181a · #5d5b18

#5b185d · #5d3818 · #1a5d18

Contrast

#183d5d as textRatioAAAA largeAAAFix
Aaon white
11.26:1passpasspassPasses AAA — no fix needed.
Aaon black
1.86:1failfailfail
  • AA: use #307abb as the text (4.63:1)
  • AAA: use #599bd4 as the text (7.06:1)
  • AA: or shift the background to #a6a6a6 (4.63:1)
  • AAA: or shift the background to #cccccc (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183d5d as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#183d5d reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183d5d
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 #183d5d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183d5d-9cadc4-df4e51-1f212d-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