Color

#5100ff

#5100ff
hex#5100ff
rgbrgb(81, 0, 255)
hslhsl(259, 100%, 50%)
oklchoklch(0.486 0.297 278.7)
Closest name: Blustering Blue (#4411ff)Relative luminance 0.0897

Tints & shades

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

Harmonies

Complementary

Open in tool →

#aeff00

#002fff · #d000ff

#ff5100 · #00ff51

Split-complementary

Open in tool →

#ffd000 · #2fff00

#ff002f · #aeff00 · #00ffd0

Contrast

#5100ff as textRatioAAAA largeAAAFix
Aaon white
7.52:1passpasspassPasses AAA — no fix needed.
Aaon black
2.79:1failfailfail
  • AA: use #854dff as the text (4.5:1)
  • AAA: use #a880ff as the text (7.2:1)
  • AA: or shift the background to #c9c9c9 (4.54:1)
  • AAA: or shift the background to #f7f7f7 (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #5100ff 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

#5100ff reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #5100ff
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 #5100ff and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5100ff-ad9cc4-dfc74e-2a1f2d-e9ebf1?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