Color

#51cff5

#51cff5
hex#51cff5
rgbrgb(81, 207, 245)
hslhsl(194, 89%, 64%)
oklchoklch(0.8 0.122 221.5)
Closest name: Blue Mana (#68c2f5)Relative luminance 0.5297

Tints & shades

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

Harmonies

Complementary

Open in tool →

#f57851

#51f5c9 · #517df5

#f551cf · #cff551

Split-complementary

Open in tool →

#f5517d · #f5c951

#c951f5 · #f57851 · #7df551

Contrast

#51cff5 as textRatioAAAA largeAAAFix
Aaon white
1.81:1failfailfail
  • AA: use #0a80a4 as the text (4.53:1)
  • AAA: use #075e78 as the text (7.29:1)
  • AA: or shift the background to #4f4f4f (4.52:1)
  • AAA: or shift the background to #303030 (7.29:1)
Aaon black
11.59:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #51cff5 as the background.

Brands using this color

Fonts for this mood

#51cff5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #51cff5
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 #51cff5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/51cff5-9cb6c4-df4e72-1f242d-e9f1ef?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