Color

#3663dd

#3663dd
hex#3663dd
rgbrgb(54, 99, 221)
hslhsl(224, 71%, 54%)
oklchoklch(0.54 0.193 265.1)
Closest name: Royal Blue (#4169e1)Relative luminance 0.1493

Colors that go with #3663dd

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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ddb136

#36b6dd · #5d36dd

#dd3663 · #63dd36

Split-complementary

Open in tool →

#dd5d36 · #b6dd36

#dd36b6 · #ddb136 · #36dd5d

Contrast

#3663dd as textRatioAAAA largeAAAFix
Aaon white
5.27:1passpassfail
  • AAA: use #214dc4 as the text (7.18:1)
Aaon black
3.99:1failpassfail
  • AA: use #4870e0 as the text (4.67:1)
  • AAA: use #7896e8 as the text (7.33:1)
  • AA: or shift the background to #ededed (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3663dd as the background.

Brands using this color

Fonts for this mood

#3663dd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3663dd
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 #3663dd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3663dd-9ca2c4-df724e-221f2d-e9eff1?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