Color

#3f10cb

#3f10cb
hex#3f10cb
rgbrgb(63, 16, 203)
hslhsl(255, 85%, 43%)
oklchoklch(0.416 0.245 278.5)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0574

Colors that go with #3f10cb

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 →

#9ccb10

#103fcb · #9c10cb

#cb3f10 · #10cb3f

Split-complementary

Open in tool →

#cb9c10 · #3fcb10

#cb103f · #9ccb10 · #10cb9c

Contrast

#3f10cb as textRatioAAAA largeAAAFix
Aaon white
9.78:1passpasspassPasses AAA — no fix needed.
Aaon black
2.15:1failfailfail
  • AA: use #805af2 as the text (4.66:1)
  • AAA: use #a184f5 as the text (7.13:1)
  • AA: or shift the background to #b0b0b0 (4.51:1)
  • AAA: or shift the background to #dbdbdb (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f10cb 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

#3f10cb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f10cb
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 #3f10cb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f10cb-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