Color

#6331b4

#6331b4
hex#6331b4
rgbrgb(99, 49, 180)
hslhsl(263, 57%, 45%)
oklchoklch(0.456 0.193 295)
Closest name: rebeccapurple (#663399)Relative luminance 0.0814

Colors that go with #6331b4

Charcoal, Royal Blue and Sea 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 →

#82b431

#3141b4 · #a531b4

#b46331 · #31b463

Split-complementary

Open in tool →

#b4a531 · #41b431

#b43141 · #82b431 · #31b4a5

Contrast

#6331b4 as textRatioAAAA largeAAAFix
Aaon white
7.99:1passpasspassPasses AAA — no fix needed.
Aaon black
2.63:1failfailfail
  • AA: use #8b5fd3 as the text (4.68:1)
  • AAA: use #a887de as the text (7.19:1)
  • AA: or shift the background to #c4c4c4 (4.58:1)
  • AAA: or shift the background to #f0f0f0 (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #6331b4 as the background.

Brands using this color

Fonts for this mood

#6331b4 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #6331b4
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 #6331b4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/6331b4-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