Color

#646bd3

#646bd3
hex#646bd3
rgbrgb(100, 107, 211)
hslhsl(236, 56%, 61%)
oklchoklch(0.574 0.157 277.3)
Closest name: slateblue (#6a5acd)Relative luminance 0.1793

Colors that go with #646bd3

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 →

#d3cc64

#64a3d3 · #9464d3

#d3646b · #6bd364

Split-complementary

Open in tool →

#d39464 · #a3d364

#d364a3 · #d3cc64 · #64d394

Contrast

#646bd3 as textRatioAAAA largeAAAFix
Aaon white
4.58:1passpassfail
  • AAA: use #3c45c8 as the text (7.3:1)
Aaon black
4.59:1passpassfail
  • AAA: use #8c91de as the text (7.22:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #646bd3 as the background.

Brands using this color

Fonts for this mood

#646bd3 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #646bd3
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 #646bd3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/646bd3-9e9cc4-df8f4e-241f2d-e9eef1?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