Color

#371dc9

#371dc9
hex#371dc9
rgbrgb(55, 29, 201)
hslhsl(249, 75%, 45%)
oklchoklch(0.417 0.238 275.3)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0591

Colors that go with #371dc9

Charcoal, Steel 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 →

#afc91d

#1d59c9 · #8d1dc9

#c9371d · #1dc937

Split-complementary

Open in tool →

#c98d1d · #59c91d

#c91d59 · #afc91d · #1dc98d

Contrast

#371dc9 as textRatioAAAA largeAAAFix
Aaon white
9.63:1passpasspassPasses AAA — no fix needed.
Aaon black
2.18:1failfailfail
  • AA: use #7763e9 as the text (4.75:1)
  • AAA: use #9a8bee as the text (7.3:1)
  • AA: or shift the background to #b3b3b3 (4.59:1)
  • AAA: or shift the background to #dedede (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #371dc9 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

#371dc9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #371dc9
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 #371dc9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/371dc9-a79cc4-dfae4e-271f2d-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