Color

#5b3871

#5b3871
hex#5b3871
rgbrgb(91, 56, 113)
hslhsl(277, 34%, 33%)
oklchoklch(0.408 0.1 311)
Closest name: Heartless (#623b70)Relative luminance 0.0624

Colors that go with #5b3871

Crimson, Denim and Midnight 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 →

#4d7138

#3e3871 · #71386a

#715b38 · #38715b

Split-complementary

Open in tool →

#6a7138 · #38713e

#713e38 · #4d7138 · #386a71

Contrast

#5b3871 as textRatioAAAA largeAAAFix
Aaon white
9.34:1passpasspassPasses AAA — no fix needed.
Aaon black
2.25:1failfailfail
  • AA: use #9362b2 as the text (4.63:1)
  • AAA: use #ad87c4 as the text (7.04:1)
  • AA: or shift the background to #b5b5b5 (4.55:1)
  • AAA: or shift the background to #e0e0e0 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #5b3871 as the background.

Brands using this color

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

mcpConnect your agent — build around #5b3871
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 #5b3871 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5b3871-b99cc4-bdcb62-2d1f2c-eae9f1?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