Color

#664bd2

#664bd2
hex#664bd2
rgbrgb(102, 75, 210)
hslhsl(252, 60%, 56%)
oklchoklch(0.52 0.198 286.5)
Closest name: slateblue (#6a5acd)Relative luminance 0.1251

Colors that go with #664bd2

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 →

#b7d24b

#4b74d2 · #aa4bd2

#d2664b · #4bd266

Split-complementary

Open in tool →

#d2aa4b · #74d24b

#d24b74 · #b7d24b · #4bd2aa

Contrast

#664bd2 as textRatioAAAA largeAAAFix
Aaon white
6:1passpassfail
  • AAA: use #593bce as the text (7.14:1)
Aaon black
3.5:1failpassfail
  • AA: use #7b64d8 as the text (4.66:1)
  • AAA: use #9a89e1 as the text (7.04:1)
  • AA: or shift the background to #e0e0e0 (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 #664bd2 as the background.

Brands using this color

Fonts for this mood

#664bd2 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #664bd2
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 #664bd2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/664bd2-a99cc4-dfb64e-281f2d-e9ecf1?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