Color

#5151c2

#5151c2
hex#5151c2
rgbrgb(81, 81, 194)
hslhsl(240, 48%, 54%)
oklchoklch(0.5 0.172 278.2)
Closest name: slateblue (#6a5acd)Relative luminance 0.1153

Colors that go with #5151c2

Charcoal, Sea Green and Amber 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 →

#c2c251

#518ac2 · #8a51c2

#c25151 · #51c251

Split-complementary

Open in tool →

#c28a51 · #8ac251

#c2518a · #c2c251 · #51c28a

Contrast

#5151c2 as textRatioAAAA largeAAAFix
Aaon white
6.35:1passpassfail
  • AAA: use #4646be as the text (7.29:1)
Aaon black
3.31:1failpassfail
  • AA: use #6c6ccb as the text (4.65:1)
  • AAA: use #8e8ed7 as the text (7:1)
  • AA: or shift the background to #d9d9d9 (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #5151c2 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

#5151c2 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #5151c2
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 #5151c2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5151c2-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