Color

#645bdc

#645bdc
hex#645bdc
rgbrgb(100, 91, 220)
hslhsl(244, 65%, 61%)
oklchoklch(0.551 0.19 281.3)
Closest name: slateblue (#6a5acd)Relative luminance 0.1536

Colors that go with #645bdc

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 →

#d4dc5b

#5b93dc · #a45bdc

#dc645b · #5bdc64

Split-complementary

Open in tool →

#dca45b · #93dc5b

#dc5b93 · #d4dc5b · #5bdca4

Contrast

#645bdc as textRatioAAAA largeAAAFix
Aaon white
5.16:1passpassfail
  • AAA: use #483dd6 as the text (7.21:1)
Aaon black
4.07:1failpassfail
  • AA: use #6f68df as the text (4.72:1)
  • AAA: use #938de7 as the text (7.2:1)
  • 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 #645bdc as the background.

Brands using this color

Fonts for this mood

#645bdc reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

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

tool url/palettes/new/645bdc-a39cc4-dfa24e-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