Color

#331dd7

#331dd7
hex#331dd7
rgbrgb(51, 29, 215)
hslhsl(247, 76%, 48%)
oklchoklch(0.431 0.254 272.9)
Closest name: Lapis on Neptune (#1f22d2)Relative luminance 0.0649

Colors that go with #331dd7

Charcoal, Cornflower Blue and Crimson 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 →

#c2d71d

#1d65d7 · #901dd7

#d7331d · #1dd733

Split-complementary

Open in tool →

#d7901d · #65d71d

#d71d65 · #c2d71d · #1dd790

Contrast

#331dd7 as textRatioAAAA largeAAAFix
Aaon white
9.14:1passpasspassPasses AAA — no fix needed.
Aaon black
2.3:1failfailfail
  • AA: use #7262ea as the text (4.65:1)
  • AAA: use #968aef as the text (7.18:1)
  • AA: or shift the background to #b8b8b8 (4.61:1)
  • AAA: or shift the background to #e3e3e3 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #331dd7 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

#331dd7 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #331dd7
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 #331dd7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/331dd7-a59cc4-dfaa4e-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