Color

#3729fa

#3729fa
hex#3729fa
rgbrgb(55, 41, 250)
hslhsl(244, 95%, 57%)
oklchoklch(0.484 0.283 271.3)
Closest name: Blustering Blue (#4411ff)Relative luminance 0.093

Colors that go with #3729fa

Charcoal, Cobalt Blue and Cornflower Blue 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 →

#ecfa29

#2983fa · #9f29fa

#fa3729 · #29fa37

Split-complementary

Open in tool →

#fa9f29 · #83fa29

#fa2983 · #ecfa29 · #29fa9f

Contrast

#3729fa as textRatioAAAA largeAAAFix
Aaon white
7.34:1passpasspassPasses AAA — no fix needed.
Aaon black
2.86:1failfailfail
  • AA: use #6a60fb as the text (4.68:1)
  • AAA: use #8f88fc as the text (7.1:1)
  • AA: or shift the background to #cccccc (4.57:1)
  • AAA: or shift the background to #fafafa (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3729fa as the background.

Brands using this color

Fonts for this mood

#3729fa reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3729fa
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 #3729fa and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3729fa-a39cc4-dfa24e-261f2d-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