Color

#3f4bcf

#3f4bcf
hex#3f4bcf
rgbrgb(63, 75, 207)
hslhsl(235, 60%, 53%)
oklchoklch(0.489 0.201 272.4)
Closest name: Blurple (#5539cc)Relative luminance 0.1059

Colors that go with #3f4bcf

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 #3f4bcf

Tints & shades

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

Harmonies

Complementary

Open in tool →

#cfc33f

#3f93cf · #7b3fcf

#cf3f4b · #4bcf3f

Split-complementary

Open in tool →

#cf7b3f · #93cf3f

#cf3f93 · #cfc33f · #3fcf7b

Contrast

#3f4bcf as textRatioAAAA largeAAAFix
Aaon white
6.73:1passpassfail
  • AAA: use #3b47ce as the text (7.05:1)
Aaon black
3.12:1failpassfail
  • AA: use #606ad7 as the text (4.54:1)
  • AAA: use #8990e1 as the text (7.14:1)
  • AA: or shift the background to #d4d4d4 (4.54:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f4bcf as the background.

Brands using this color

Fonts for this mood

#3f4bcf reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f4bcf
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 #3f4bcf and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4bcf-9e9cc4-df8d4e-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