Color

#371db9

#371db9
hex#371db9
rgbrgb(55, 29, 185)
hslhsl(250, 73%, 42%)
oklchoklch(0.398 0.221 277.1)
Closest name: Galactic Highway (#3311bb)Relative luminance 0.0519

Colors that go with #371db9

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 →

#9fb91d

#1d51b9 · #851db9

#b9371d · #1db937

Split-complementary

Open in tool →

#b9851d · #51b91d

#b91d51 · #9fb91d · #1db985

Contrast

#371db9 as textRatioAAAA largeAAAFix
Aaon white
10.3:1passpasspassPasses AAA — no fix needed.
Aaon black
2.04:1failfailfail
  • AA: use #7760e6 as the text (4.6:1)
  • AAA: use #9988ec as the text (7.09:1)
  • AA: or shift the background to #adadad (4.59:1)
  • AAA: or shift the background to #d6d6d6 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #371db9 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

#371db9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #371db9
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 #371db9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/371db9-a79cc4-dfb14e-281f2d-e9ecf1?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