Color

#5151a4

#5151a4
hex#5151a4
rgbrgb(81, 81, 164)
hslhsl(240, 34%, 48%)
oklchoklch(0.478 0.13 280.3)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.1031

Colors that go with #5151a4

Charcoal, Amber and 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 →

#a4a451

#517aa4 · #7a51a4

#a45151 · #51a451

Split-complementary

Open in tool →

#a47a51 · #7aa451

#a4517a · #a4a451 · #51a47a

Contrast

#5151a4 as textRatioAAAA largeAAAFix
Aaon white
6.86:1passpassfail
  • AAA: use #4f4fa1 as the text (7.08:1)
Aaon black
3.06:1failpassfail
  • AA: use #6f6fb8 as the text (4.64:1)
  • AAA: use #9292c9 as the text (7.18:1)
  • AA: or shift the background to #d4d4d4 (4.63:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #5151a4 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 #5151a4
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 #5151a4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5151a4-a19cc4-df994e-251f2d-e9edf1?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