Color

#3755cd

#3755cd
hex#3755cd
rgbrgb(55, 85, 205)
hslhsl(228, 60%, 51%)
oklchoklch(0.501 0.189 268.1)
Closest name: Denim (#1560bd)Relative luminance 0.1172

Colors that go with #3755cd

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 →

#cdaf37

#37a0cd · #6437cd

#cd3755 · #55cd37

Split-complementary

Open in tool →

#cd6437 · #a0cd37

#cd37a0 · #cdaf37 · #37cd64

Contrast

#3755cd as textRatioAAAA largeAAAFix
Aaon white
6.28:1passpassfail
  • AAA: use #304dc0 as the text (7.12:1)
Aaon black
3.34:1failpassfail
  • AA: use #546dd4 as the text (4.52:1)
  • AAA: use #8193df as the text (7.17:1)
  • AA: or shift the background to #dbdbdb (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 #3755cd as the background.

Brands using this color

Fonts for this mood

#3755cd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3755cd
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 #3755cd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3755cd-9c9fc4-df7c4e-231f2d-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