Color

#6663bb

#6663bb
hex#6663bb
rgbrgb(102, 99, 187)
hslhsl(242, 39%, 56%)
oklchoklch(0.545 0.134 282.5)
Closest name: Bellflower (#5d66aa)Relative luminance 0.1534

Colors that go with #6663bb

Charcoal, Sea Green and Amber 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 →

#b8bb63

#638cbb · #9263bb

#bb6663 · #63bb66

Split-complementary

Open in tool →

#bb9263 · #8cbb63

#bb638c · #b8bb63 · #63bb92

Contrast

#6663bb as textRatioAAAA largeAAAFix
Aaon white
5.16:1passpassfail
  • AAA: use #4f4cae as the text (7.05:1)
Aaon black
4.07:1failpassfail
  • AA: use #706ebf as the text (4.67:1)
  • AAA: use #9391cf as the text (7.19:1)
  • AA: or shift the background to #f0f0f0 (4.53:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #6663bb as the background.

Brands using this color

Fonts for this mood

#6663bb reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #6663bb
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 #6663bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/6663bb-a29cc4-df9e4e-261f2d-e9edf1?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