Color

#645ec9

#645ec9
hex#645ec9
rgbrgb(100, 94, 201)
hslhsl(243, 50%, 58%)
oklchoklch(0.543 0.161 282.1)
Closest name: slateblue (#6a5acd)Relative luminance 0.1493

Colors that go with #645ec9

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 →

#c4c95e

#5e8fc9 · #995ec9

#c9645e · #5ec964

Split-complementary

Open in tool →

#c9995e · #8fc95e

#c95e8f · #c4c95e · #5ec999

Contrast

#645ec9 as textRatioAAAA largeAAAFix
Aaon white
5.27:1passpassfail
  • AAA: use #4a44c1 as the text (7.27:1)
Aaon black
3.99:1failpassfail
  • AA: use #6f6acd as the text (4.62:1)
  • AAA: use #9490da as the text (7.26:1)
  • AA: or shift the background to #f0f0f0 (4.62:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #645ec9 as the background.

Brands using this color

Fonts for this mood

#645ec9 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #645ec9
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 #645ec9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/645ec9-a39cc4-dfa04e-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