Color

#313b3f

#313b3f
hex#313b3f
rgbrgb(49, 59, 63)
hslhsl(197, 13%, 22%)
oklchoklch(0.345 0.015 223.9)
Closest name: Artist’s Charcoal (#37393e)Relative luminance 0.0414

Colors that go with #313b3f

Amber, Blue and Blush Pink 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 →

#3f3531

#313f3c · #31343f

#3f313b · #3b3f31

Split-complementary

Open in tool →

#3f3134 · #3f3c31

#3c313f · #3f3531 · #343f31

Contrast

#313b3f as textRatioAAAA largeAAAFix
Aaon white
11.49:1passpasspassPasses AAA — no fix needed.
Aaon black
1.83:1failfailfail
  • AA: use #647982 as the text (4.6:1)
  • AAA: use #869aa2 as the text (7.16:1)
  • AA: or shift the background to #a3a3a3 (4.55:1)
  • AAA: or shift the background to #cccccc (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #313b3f as the background.

Brands using this color

Fonts for this mood

#313b3f reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313b3f
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 #313b3f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313b3f-9cb4c4-df4e6b-1f232d-e9f1ef?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