Color

#631bb6

#631bb6
hex#631bb6
rgbrgb(99, 27, 182)
hslhsl(268, 74%, 41%)
oklchoklch(0.436 0.216 296.9)
Closest name: Fuchsia Nebula (#7722aa)Relative luminance 0.0681

Colors that go with #631bb6

Tomato, Olive Green and Charcoal 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 →

#6eb61b

#1b20b6 · #b11bb6

#b6631b · #1bb663

Split-complementary

Open in tool →

#b6b11b · #20b61b

#b61b20 · #6eb61b · #1bb6b1

Contrast

#631bb6 as textRatioAAAA largeAAAFix
Aaon white
8.89:1passpasspassPasses AAA — no fix needed.
Aaon black
2.36:1failfailfail
  • AA: use #9752e5 as the text (4.65:1)
  • AAA: use #b17eec as the text (7.06:1)
  • AA: or shift the background to #bababa (4.58:1)
  • AAA: or shift the background to #e6e6e6 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #631bb6 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

#631bb6 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #631bb6
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 #631bb6 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/631bb6-b39cc4-dfdc4e-2c1f2d-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