Color

#3911bb

#3911bb
hex#3911bb
rgbrgb(57, 17, 187)
hslhsl(254, 83%, 40%)
oklchoklch(0.393 0.229 278.2)
Closest name: Galactic Highway (#3311bb)Relative luminance 0.0486

Colors that go with #3911bb

Charcoal, Blue and Cornflower Blue 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 →

#93bb11

#113ebb · #8e11bb

#bb3911 · #11bb39

Split-complementary

Open in tool →

#bb8e11 · #3ebb11

#bb113e · #93bb11 · #11bb8e

Contrast

#3911bb as textRatioAAAA largeAAAFix
Aaon white
10.65:1passpasspassPasses AAA — no fix needed.
Aaon black
1.97:1failfailfail
  • AA: use #7e5cf0 as the text (4.68:1)
  • AAA: use #9f86f4 as the text (7.19:1)
  • AA: or shift the background to #ababab (4.64:1)
  • AAA: or shift the background to #d4d4d4 (7.19:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3911bb as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#3911bb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3911bb
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 #3911bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3911bb-aa9cc4-dfbb4e-291f2d-e9ebf1?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