Color

#431d81

#431d81
hex#431d81
rgbrgb(67, 29, 129)
hslhsl(263, 63%, 31%)
oklchoklch(0.35 0.155 294.2)
Closest name: Galactic Civilization (#442288)Relative luminance 0.0366

Colors that go with #431d81

Royal Blue, Charcoal and Crimson 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 →

#5b811d

#1d2981 · #751d81

#81431d · #1d8143

Split-complementary

Open in tool →

#81751d · #29811d

#811d29 · #5b811d · #1d8175

Contrast

#431d81 as textRatioAAAA largeAAAFix
Aaon white
12.13:1passpasspassPasses AAA — no fix needed.
Aaon black
1.73:1failfailfail
  • AA: use #8a59d9 as the text (4.51:1)
  • AAA: use #aa86e4 as the text (7.24:1)
  • AA: or shift the background to #9e9e9e (4.53:1)
  • AAA: or shift the background to #c7c7c7 (7.17:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #431d81 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

#431d81 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #431d81
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 #431d81 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/431d81-b09cc4-dfd04e-2b1f2d-e9eaf1?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