Color

#243f5c

#243f5c
hex#243f5c
rgbrgb(36, 63, 92)
hslhsl(211, 44%, 25%)
oklchoklch(0.36 0.06 251.4)
Closest name: Capital Blue (#1a4157)Relative luminance 0.047

Colors that go with #243f5c

Dark Olive Green, 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 →

#5c4124

#245b5c · #25245c

#5c243f · #3f5c24

Split-complementary

Open in tool →

#5c2524 · #5b5c24

#5c245b · #5c4124 · #245c25

Contrast

#243f5c as textRatioAAAA largeAAAFix
Aaon white
10.82:1passpasspassPasses AAA — no fix needed.
Aaon black
1.94:1failfailfail
  • AA: use #4579b0 as the text (4.61:1)
  • AAA: use #709ac7 as the text (7.14:1)
  • AA: or shift the background to #a8a8a8 (4.55:1)
  • AAA: or shift the background to #d1d1d1 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #243f5c as the background.

Brands using this color

Fonts for this mood

#243f5c reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #243f5c
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 #243f5c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/243f5c-9cabc4-df534e-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