Color

#664db3

#664db3
hex#664db3
rgbrgb(102, 77, 179)
hslhsl(255, 40%, 50%)
oklchoklch(0.499 0.155 291)
Closest name: slateblue (#6a5acd)Relative luminance 0.1139

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#99b34d

#4d66b3 · #994db3

#b3664d · #4db366

Split-complementary

Open in tool →

#b3994d · #66b34d

#b34d66 · #99b34d · #4db399

Contrast

#664db3 as textRatioAAAA largeAAAFix
Aaon white
6.41:1passpassfail
  • AAA: use #6048a8 as the text (7.02:1)
Aaon black
3.28:1failpassfail
  • AA: use #7e69bf as the text (4.66:1)
  • AAA: use #9d8dce as the text (7.13:1)
  • AA: or shift the background to #d9d9d9 (4.54:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #664db3 as the background.

Brands using this color

Fonts for this mood

#664db3 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #664db3
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #664db3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/664db3-ab9cc4-dfbd4e-291f2d-e9ebf1?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