Color

#3f50cf

#3f50cf
hex#3f50cf
rgbrgb(63, 80, 207)
hslhsl(233, 60%, 53%)
oklchoklch(0.497 0.195 271.4)
Closest name: Blurple (#5539cc)Relative luminance 0.113

Colors that go with #3f50cf

Charcoal, Sea Green and Amber 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.

Real palettes that use #3f50cf

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#cfbe3f

#3f98cf · #763fcf

#cf3f50 · #50cf3f

Split-complementary

Open in tool →

#cf763f · #98cf3f

#cf3f98 · #cfbe3f · #3fcf76

Contrast

#3f50cf as textRatioAAAA largeAAAFix
Aaon white
6.44:1passpassfail
  • AAA: use #3749cd as the text (7.01:1)
Aaon black
3.26:1failpassfail
  • AA: use #606ed7 as the text (4.71:1)
  • AAA: use #858fe0 as the text (7:1)
  • AA: or shift the background to #d9d9d9 (4.56:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f50cf as the background.

Brands using this color

Fonts for this mood

#3f50cf reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f50cf
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 #3f50cf and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f50cf-9c9cc4-df884e-241f2d-e9eef1?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