Color

#661cb5

#661cb5
hex#661cb5
rgbrgb(102, 28, 181)
hslhsl(269, 73%, 41%)
oklchoklch(0.44 0.214 298.4)
Closest name: Fuchsia Nebula (#7722aa)Relative luminance 0.0699

Colors that go with #661cb5

Olive Green, Charcoal and Denim 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 →

#6bb51c

#1c1fb5 · #b21cb5

#b5661c · #1cb566

Split-complementary

Open in tool →

#b5b21c · #1fb51c

#b51c1f · #6bb51c · #1cb5b2

Contrast

#661cb5 as textRatioAAAA largeAAAFix
Aaon white
8.76:1passpasspassPasses AAA — no fix needed.
Aaon black
2.4:1failfailfail
  • AA: use #974fe3 as the text (4.54:1)
  • AAA: use #b37feb as the text (7.15:1)
  • AA: or shift the background to #bababa (4.51:1)
  • AAA: or shift the background to #e6e6e6 (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #661cb5 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#661cb5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #661cb5
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 #661cb5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/661cb5-b49cc4-cbcb62-2c1f2d-e9e9f1?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