Color

#3720cb

#3720cb
hex#3720cb
rgbrgb(55, 32, 203)
hslhsl(248, 73%, 46%)
oklchoklch(0.422 0.239 275)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0616

Colors that go with #3720cb

Charcoal, Cornflower Blue and Crimson 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 →

#b4cb20

#205ecb · #8c20cb

#cb3720 · #20cb37

Split-complementary

Open in tool →

#cb8c20 · #5ecb20

#cb205e · #b4cb20 · #20cb8c

Contrast

#3720cb as textRatioAAAA largeAAAFix
Aaon white
9.41:1passpasspassPasses AAA — no fix needed.
Aaon black
2.23:1failfailfail
  • AA: use #7260e6 as the text (4.53:1)
  • AAA: use #9588ec as the text (7.01:1)
  • AA: or shift the background to #b5b5b5 (4.59:1)
  • AAA: or shift the background to #e0e0e0 (7.13:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3720cb 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

#3720cb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3720cb
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 #3720cb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3720cb-a69cc4-dfac4e-271f2d-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