Color

#3f13dd

#3f13dd
hex#3f13dd
rgbrgb(63, 19, 221)
hslhsl(253, 84%, 47%)
oklchoklch(0.439 0.262 276.3)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0674

Colors that go with #3f13dd

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 →

#b1dd13

#134cdd · #a313dd

#dd3f13 · #13dd3f

Split-complementary

Open in tool →

#dda313 · #4cdd13

#dd134c · #b1dd13 · #13dda3

Contrast

#3f13dd as textRatioAAAA largeAAAFix
Aaon white
8.94:1passpasspassPasses AAA — no fix needed.
Aaon black
2.35:1failfailfail
  • AA: use #7b5bf1 as the text (4.61:1)
  • AAA: use #9d85f4 as the text (7.09:1)
  • AA: or shift the background to #b8b8b8 (4.51:1)
  • AAA: or shift the background to #e6e6e6 (7.16:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f13dd 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

#3f13dd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f13dd
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 #3f13dd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f13dd-a99cc4-dfb84e-281f2d-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