Color

#3681dd

#3681dd
hex#3681dd
rgbrgb(54, 129, 221)
hslhsl(213, 71%, 54%)
oklchoklch(0.603 0.158 255.4)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2171

Colors that go with #3681dd

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 →

#dd9236

#36d5dd · #3f36dd

#dd3681 · #81dd36

Split-complementary

Open in tool →

#dd3f36 · #d5dd36

#dd36d5 · #dd9236 · #36dd3f

Contrast

#3681dd as textRatioAAAA largeAAAFix
Aaon white
3.93:1failpassfail
  • AA: use #2474d6 as the text (4.62:1)
  • AAA: use #1b58a1 as the text (7.1:1)
  • AA: or shift the background to #171717 (4.56:1)
Aaon black
5.34:1passpassfail
  • AAA: use #5e9ae4 as the text (7.22:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3681dd as the background.

Brands using this color

Fonts for this mood

#3681dd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3681dd
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 #3681dd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3681dd-9ca9c4-df584e-1f202d-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