Color

#3f375d

#3f375d
hex#3f375d
rgbrgb(63, 55, 93)
hslhsl(253, 26%, 29%)
oklchoklch(0.363 0.065 292.5)
Closest name: Call It a Night (#42364c)Relative luminance 0.0458

Colors that go with #3f375d

Steel Blue, Teal and Dark Olive Green 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 →

#555d37

#37425d · #52375d

#5d3f37 · #375d3f

Split-complementary

Open in tool →

#5d5237 · #425d37

#5d3742 · #555d37 · #375d52

Contrast

#3f375d as textRatioAAAA largeAAAFix
Aaon white
10.96:1passpasspassPasses AAA — no fix needed.
Aaon black
1.92:1failfailfail
  • AA: use #7b6eaa as the text (4.65:1)
  • AAA: use #998fbd as the text (7.02:1)
  • AA: or shift the background to #a6a6a6 (4.5:1)
  • AAA: or shift the background to #cfcfcf (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f375d as the background.

Brands using this color

Fonts for this mood

#3f375d reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f375d
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 #3f375d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f375d-a99cc4-dfb84e-281f2d-e9ebf1?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