Color

#3d57b3

#3d57b3
hex#3d57b3
rgbrgb(61, 87, 179)
hslhsl(227, 49%, 47%)
oklchoklch(0.488 0.149 268.5)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.1106

Colors that go with #3d57b3

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 →

#b3993d

#3d91b3 · #5e3db3

#b33d57 · #57b33d

Split-complementary

Open in tool →

#b35e3d · #91b33d

#b33d91 · #b3993d · #3db35e

Contrast

#3d57b3 as textRatioAAAA largeAAAFix
Aaon white
6.54:1passpassfail
  • AAA: use #3951a7 as the text (7.22:1)
Aaon black
3.21:1failpassfail
  • AA: use #5870c6 as the text (4.55:1)
  • AAA: use #8293d4 as the text (7.07:1)
  • AA: or shift the background to #d9d9d9 (4.63:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3d57b3 as the background.

Brands using this color

Fonts for this mood

#3d57b3 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3d57b3
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 #3d57b3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3d57b3-9ca0c4-df7a4e-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