Color

#3904d7

#3904d7
hex#3904d7
rgbrgb(57, 4, 215)
hslhsl(255, 96%, 43%)
oklchoklch(0.421 0.262 275.3)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0586

Colors that go with #3904d7

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 →

#a2d704

#0439d7 · #a204d7

#d73904 · #04d739

Split-complementary

Open in tool →

#d7a204 · #39d704

#d70439 · #a2d704 · #04d7a2

Contrast

#3904d7 as textRatioAAAA largeAAAFix
Aaon white
9.67:1passpasspassPasses AAA — no fix needed.
Aaon black
2.17:1failfailfail
  • AA: use #7f55fc as the text (4.61:1)
  • AAA: use #a182fc as the text (7.11:1)
  • AA: or shift the background to #b3b3b3 (4.61:1)
  • AAA: or shift the background to #dedede (7.18:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3904d7 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

#3904d7 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3904d7
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 #3904d7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3904d7-ab9cc4-dfbd4e-291f2d-e9ebf1?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