Color

#665dc0

#665dc0
hex#665dc0
rgbrgb(102, 93, 192)
hslhsl(245, 44%, 56%)
oklchoklch(0.537 0.15 284.3)
Closest name: slateblue (#6a5acd)Relative luminance 0.1446

Colors that go with #665dc0

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 →

#b8c05d

#5d87c0 · #975dc0

#c0665d · #5dc066

Split-complementary

Open in tool →

#c0975d · #87c05d

#c05d87 · #b8c05d · #5dc097

Contrast

#665dc0 as textRatioAAAA largeAAAFix
Aaon white
5.4:1passpassfail
  • AAA: use #5147b8 as the text (7.13:1)
Aaon black
3.89:1failpassfail
  • AA: use #746cc6 as the text (4.7:1)
  • AAA: use #9691d4 as the text (7.3:1)
  • AA: or shift the background to #ebebeb (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 #665dc0 as the background.

Brands using this color

Fonts for this mood

#665dc0 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #665dc0
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 #665dc0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/665dc0-a49cc4-dfa54e-261f2d-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