Color

#313a54

#313a54
hex#313a54
rgbrgb(49, 58, 84)
hslhsl(225, 26%, 26%)
oklchoklch(0.352 0.047 269.2)
Closest name: Call It a Night (#42364c)Relative luminance 0.0432

Colors that go with #313a54

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 →

#544b31

#314b54 · #3a3154

#54313a · #3a5431

Split-complementary

Open in tool →

#543a31 · #4b5431

#54314b · #544b31 · #31543a

Contrast

#313a54 as textRatioAAAA largeAAAFix
Aaon white
11.27:1passpasspassPasses AAA — no fix needed.
Aaon black
1.86:1failfailfail
  • AA: use #6575a4 as the text (4.63:1)
  • AAA: use #8b97bb as the text (7.24:1)
  • AA: or shift the background to #a6a6a6 (4.63:1)
  • AAA: or shift the background to #cccccc (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #313a54 as the background.

Brands using this color

Fonts for this mood

#313a54 reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313a54
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 #313a54 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313a54-9ca1c4-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