Color

#665bdc

#665bdc
hex#665bdc
rgbrgb(102, 91, 220)
hslhsl(245, 65%, 61%)
oklchoklch(0.553 0.19 282.1)
Closest name: slateblue (#6a5acd)Relative luminance 0.1547

Colors that go with #665bdc

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 →

#d1dc5b

#5b91dc · #a65bdc

#dc665b · #5bdc66

Split-complementary

Open in tool →

#dca65b · #91dc5b

#dc5b91 · #d1dc5b · #5bdca6

Contrast

#665bdc as textRatioAAAA largeAAAFix
Aaon white
5.13:1passpassfail
  • AAA: use #4a3dd6 as the text (7.17:1)
Aaon black
4.09:1failpassfail
  • AA: use #6e63de as the text (4.5:1)
  • AAA: use #958de7 as the text (7.24:1)
  • AA: or shift the background to #f0f0f0 (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #665bdc as the background.

Brands using this color

Fonts for this mood

#665bdc reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

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

tool url/palettes/new/665bdc-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