Color

#631dbf

#631dbf
hex#631dbf
rgbrgb(99, 29, 191)
hslhsl(266, 74%, 43%)
oklchoklch(0.446 0.223 294.6)
Closest name: Blurple (#5539cc)Relative luminance 0.0729

Colors that go with #631dbf

Royal Blue, Tomato and 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 →

#78bf1d

#1d27bf · #b41dbf

#bf631d · #1dbf63

Split-complementary

Open in tool →

#bfb41d · #27bf1d

#bf1d27 · #78bf1d · #1dbfb4

Contrast

#631dbf as textRatioAAAA largeAAAFix
Aaon white
8.54:1passpasspassPasses AAA — no fix needed.
Aaon black
2.46:1failfailfail
  • AA: use #9252e5 as the text (4.56:1)
  • AAA: use #b183ec as the text (7.33:1)
  • AA: or shift the background to #bdbdbd (4.55:1)
  • AAA: or shift the background to #ebebeb (7.16:1)

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

Brands using this color

Fonts for this mood

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

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

tool url/palettes/new/631dbf-b29cc4-dfd74e-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