Color

#313b59

#313b59
hex#313b59
rgbrgb(49, 59, 89)
hslhsl(225, 29%, 27%)
oklchoklch(0.357 0.054 269.5)
Closest name: Black Turmeric (#2c4364)Relative luminance 0.045

Colors that go with #313b59

Dark Olive Green, Sea Green and Steel 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 →

#594f31

#314f59 · #3b3159

#59313b · #3b5931

Split-complementary

Open in tool →

#593b31 · #4f5931

#59314f · #594f31 · #31593b

Contrast

#313b59 as textRatioAAAA largeAAAFix
Aaon white
11.05:1passpasspassPasses AAA — no fix needed.
Aaon black
1.9:1failfailfail
  • AA: use #6173a8 as the text (4.53:1)
  • AAA: use #8996be as the text (7.17:1)
  • AA: or shift the background to #a6a6a6 (4.54:1)
  • AAA: or shift the background to #cfcfcf (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 #313b59 as the background.

Brands using this color

Fonts for this mood

#313b59 reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313b59
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 #313b59 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313b59-9ca1c4-df754e-221f2d-e9eff1?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