Color

#3f7ef3

#3f7ef3
hex#3f7ef3
rgbrgb(63, 126, 243)
hslhsl(219, 88%, 60%)
oklchoklch(0.614 0.188 261.4)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2245

Colors that go with #3f7ef3

Charcoal, Crimson and Copper 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 →

#f3b43f

#3fd8f3 · #5a3ff3

#f33f7e · #7ef33f

Split-complementary

Open in tool →

#f35a3f · #d8f33f

#f33fd8 · #f3b43f · #3ff35a

Contrast

#3f7ef3 as textRatioAAAA largeAAAFix
Aaon white
3.83:1failpassfail
  • AA: use #276ef1 as the text (4.58:1)
  • AAA: use #0d4fc9 as the text (7.05:1)
  • AA: or shift the background to #1a1a1a (4.55:1)
Aaon black
5.49:1passpassfail
  • AAA: use #6195f5 as the text (7.13:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f7ef3 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#3f7ef3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f7ef3
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 #3f7ef3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f7ef3-9ca5c4-df664e-211f2d-e9f0f1?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