Color

#51aeec

#51aeec
hex#51aeec
rgbrgb(81, 174, 236)
hslhsl(204, 80%, 62%)
oklchoklch(0.721 0.126 240.9)
Closest name: Cerulean (#55aaee)Relative luminance 0.3808

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ec8f51

#51ecdc · #5160ec

#ec51ae · #aeec51

Split-complementary

Open in tool →

#ec5160 · #ecdc51

#dc51ec · #ec8f51 · #60ec51

Contrast

#51aeec as textRatioAAAA largeAAAFix
Aaon white
2.44:1failfailfail
  • AA: use #1579bc as the text (4.67:1)
  • AAA: use #105c8e as the text (7.13:1)
  • AA: or shift the background to #3b3b3b (4.6:1)
  • AAA: or shift the background to #1a1a1a (7.14:1)
Aaon black
8.62:1passpasspassPasses 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 #51aeec as the background.

Brands using this color

Fonts for this mood

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

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

tool url/palettes/new/51aeec-9cafc4-df4e5a-1f222d-e9f1f0?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