Color

#3f9fde

#3f9fde
hex#3f9fde
rgbrgb(63, 159, 222)
hslhsl(204, 71%, 56%)
oklchoklch(0.674 0.129 241.4)
Closest name: Blue Burst (#309cd0)Relative luminance 0.3113

Colors that go with #3f9fde

Charcoal, Tomato and Peru 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 →

#de7f3f

#3fdecf · #3f4fde

#de3f9f · #9fde3f

Split-complementary

Open in tool →

#de3f4f · #decf3f

#cf3fde · #de7f3f · #4fde3f

Contrast

#3f9fde as textRatioAAAA largeAAAFix
Aaon white
2.91:1failfailfail
  • AA: use #1f7ab7 as the text (4.64:1)
  • AAA: use #185d8c as the text (7.04:1)
  • AA: or shift the background to #303030 (4.54:1)
  • AAA: or shift the background to #050505 (7.01:1)
Aaon black
7.23:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f9fde 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

#3f9fde reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f9fde
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 #3f9fde and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f9fde-9cafc4-df4e5a-1f222d-e9f1f0?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