Color

#183e54

#183e54
hex#183e54
rgbrgb(24, 62, 84)
hslhsl(202, 56%, 21%)
oklchoklch(0.347 0.058 237.1)
Closest name: Capital Blue (#1a4157)Relative luminance 0.0428

Colors that go with #183e54

Royal Blue, 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 →

#542e18

#18544c · #182054

#54183e · #3e5418

Split-complementary

Open in tool →

#541820 · #544c18

#4c1854 · #542e18 · #205418

Contrast

#183e54 as textRatioAAAA largeAAAFix
Aaon white
11.32:1passpasspassPasses AAA — no fix needed.
Aaon black
1.86:1failfailfail
  • AA: use #2f7ba7 as the text (4.51:1)
  • AAA: use #4c9dcd as the text (7.01:1)
  • AA: or shift the background to #a6a6a6 (4.65:1)
  • AAA: or shift the background to #cccccc (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183e54 as the background.

Brands using this color

Fonts for this mood

#183e54 reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183e54
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 #183e54 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183e54-9cb1c4-df4e5f-1f222d-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