Color

#3f404a

#3f404a
hex#3f404a
rgbrgb(63, 64, 74)
hslhsl(235, 8%, 27%)
oklchoklch(0.374 0.017 281)
Closest name: Arsenic (#3b444b)Relative luminance 0.0522

Colors that go with #3f404a

Blue, Blush Pink and Burlywood 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.

Real palettes that use #3f404a

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#4a493f

#3f464a · #443f4a

#4a3f40 · #404a3f

Split-complementary

Open in tool →

#4a443f · #464a3f

#4a3f46 · #4a493f · #3f4a44

Contrast

#3f404a as textRatioAAAA largeAAAFix
Aaon white
10.28:1passpasspassPasses AAA — no fix needed.
Aaon black
2.04:1failfailfail
  • AA: use #737587 as the text (4.62:1)
  • AAA: use #9495a4 as the text (7.09:1)
  • AA: or shift the background to #adadad (4.58:1)
  • AAA: or shift the background to #d6d6d6 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f404a as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#3f404a reads as muted, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f404a
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 #3f404a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f404a-9e9cc4-df8d4e-241f2d-e9eef1?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