Color

#403f5a

#403f5a
hex#403f5a
rgbrgb(64, 63, 90)
hslhsl(242, 18%, 30%)
oklchoklch(0.38 0.046 285.7)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.0538

Colors that go with #403f5a

Sea Green, Steel Blue and Teal 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 →

#595a3f

#3f4c5a · #4d3f5a

#5a403f · #3f5a40

Split-complementary

Open in tool →

#5a4d3f · #4c5a3f

#5a3f4c · #595a3f · #3f5a4d

Contrast

#403f5a as textRatioAAAA largeAAAFix
Aaon white
10.11:1passpasspassPasses AAA — no fix needed.
Aaon black
2.08:1failfailfail
  • AA: use #73729d as the text (4.62:1)
  • AAA: use #9493b4 as the text (7.09:1)
  • AA: or shift the background to #adadad (4.51:1)
  • AAA: or shift the background to #d9d9d9 (7.16:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #403f5a 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

#403f5a reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #403f5a
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 #403f5a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/403f5a-a29cc4-df9e4e-261f2d-e9edf1?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