Color

#403d5c

#403d5c
hex#403d5c
rgbrgb(64, 61, 92)
hslhsl(246, 20%, 30%)
oklchoklch(0.377 0.053 288)
Closest name: Call It a Night (#42364c)Relative luminance 0.052

Colors that go with #403d5c

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 →

#595c3d

#3d495c · #503d5c

#5c403d · #3d5c40

Split-complementary

Open in tool →

#5c503d · #495c3d

#5c3d49 · #595c3d · #3d5c50

Contrast

#403d5c as textRatioAAAA largeAAAFix
Aaon white
10.29:1passpasspassPasses AAA — no fix needed.
Aaon black
2.04:1failfailfail
  • AA: use #746f9f as the text (4.52:1)
  • AAA: use #9591b6 as the text (7:1)
  • AA: or shift the background to #adadad (4.59:1)
  • AAA: or shift the background to #d6d6d6 (7.08:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #403d5c as the background.

Brands using this color

Fonts for this mood

#403d5c reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #403d5c
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 #403d5c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/403d5c-a59cc4-dfa74e-271f2d-e9ecf1?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