Color

#3f183d

#3f183d
hex#3f183d
rgbrgb(63, 24, 61)
hslhsl(303, 45%, 17%)
oklchoklch(0.284 0.082 329.5)
Closest name: Velvet Cosmos (#441144)Relative luminance 0.0205

Colors that go with #3f183d

Charcoal, Sea Green and Slate 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 →

#183f1a

#2d183f · #3f1829

#3d3f18 · #183d3f

Split-complementary

Open in tool →

#293f18 · #183f2d

#3f2d18 · #183f1a · #18293f

Contrast

#3f183d as textRatioAAAA largeAAAFix
Aaon white
14.9:1passpasspassPasses AAA — no fix needed.
Aaon black
1.41:1failfailfail
  • AA: use #b946b3 as the text (4.59:1)
  • AAA: use #cd7ac8 as the text (7.21:1)
  • AA: or shift the background to #8f8f8f (4.61:1)
  • AAA: or shift the background to #b3b3b3 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f183d 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

#3f183d reads as warm, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f183d
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 #3f183d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f183d-c19fbb-8fcb62-2d1f26-eee9f1?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