Color

#403d51

#403d51
hex#403d51
rgbrgb(64, 61, 81)
hslhsl(249, 14%, 28%)
oklchoklch(0.371 0.034 291.5)
Closest name: Call It a Night (#42364c)Relative luminance 0.0502

Colors that go with #403d51

Dark Olive Green, Sea Green and Steel 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 →

#4e513d

#3d4451 · #4a3d51

#51403d · #3d5140

Split-complementary

Open in tool →

#514a3d · #44513d

#513d44 · #4e513d · #3d514a

Contrast

#403d51 as textRatioAAAA largeAAAFix
Aaon white
10.48:1passpasspassPasses AAA — no fix needed.
Aaon black
2:1failfailfail
  • AA: use #767194 as the text (4.56:1)
  • AAA: use #9793ae as the text (7.1:1)
  • AA: or shift the background to #ababab (4.56:1)
  • AAA: or shift the background to #d4d4d4 (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 #403d51 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

#403d51 reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #403d51
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 #403d51 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/403d51-a79cc4-dfae4e-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