Color

#331b9d

#331b9d
hex#331b9d
rgbrgb(51, 27, 157)
hslhsl(251, 71%, 36%)
oklchoklch(0.361 0.191 279.3)
Closest name: Depths of Night (#2c319b)Relative luminance 0.0392

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#859d1b

#1b449d · #741b9d

#9d331b · #1b9d33

Split-complementary

Open in tool →

#9d741b · #449d1b

#9d1b44 · #859d1b · #1b9d74

Contrast

#331b9d as textRatioAAAA largeAAAFix
Aaon white
11.77:1passpasspassPasses AAA — no fix needed.
Aaon black
1.78:1failfailfail
  • AA: use #7a62e4 as the text (4.69:1)
  • AAA: use #9b89eb as the text (7.17:1)
  • AA: or shift the background to #a1a1a1 (4.56:1)
  • AAA: or shift the background to #c9c9c9 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #331b9d 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

#331b9d reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #331b9d
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #331b9d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/331b9d-a89cc4-dfb34e-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