Color

#3b5bb5

#3b5bb5
hex#3b5bb5
rgbrgb(59, 91, 181)
hslhsl(224, 51%, 47%)
oklchoklch(0.496 0.147 266.4)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.1175

Colors that go with #3b5bb5

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 →

#b5943b

#3b98b5 · #573bb5

#b53b5b · #5bb53b

Split-complementary

Open in tool →

#b5573b · #98b53b

#b53b98 · #b5943b · #3bb557

Contrast

#3b5bb5 as textRatioAAAA largeAAAFix
Aaon white
6.27:1passpassfail
  • AAA: use #3654a6 as the text (7.06:1)
Aaon black
3.35:1failpassfail
  • AA: use #5271c7 as the text (4.55:1)
  • AAA: use #7c94d5 as the text (7.05:1)
  • AA: or shift the background to #dbdbdb (4.53:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3b5bb5 as the background.

Brands using this color

Fonts for this mood

#3b5bb5 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3b5bb5
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 #3b5bb5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3b5bb5-9ca2c4-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