Color

#666af5

#666af5
hex#666af5
rgbrgb(102, 106, 245)
hslhsl(238, 88%, 68%)
oklchoklch(0.597 0.204 277)
Closest name: mediumslateblue (#7b68ee)Relative luminance 0.1973

Colors that go with #666af5

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 →

#f5f066

#66b2f5 · #a966f5

#f5666a · #6af566

Split-complementary

Open in tool →

#f5a966 · #b2f566

#f566b2 · #f5f066 · #66f5a9

Contrast

#666af5 as textRatioAAAA largeAAAFix
Aaon white
4.25:1failpassfail
  • AA: use #5c61f5 as the text (4.68:1)
  • AAA: use #3137f2 as the text (7.1:1)
  • AA: or shift the background to #0f0f0f (4.51:1)
Aaon black
4.95:1passpassfail
  • AAA: use #878bf7 as the text (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666af5 as the background.

Brands using this color

Fonts for this mood

#666af5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #666af5
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 #666af5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/666af5-9f9cc4-df944e-251f2d-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