Color

#5bb3fb

#5bb3fb
hex#5bb3fb
rgbrgb(91, 179, 251)
hslhsl(207, 95%, 67%)
oklchoklch(0.743 0.135 245.7)
Closest name: Cerulean (#55aaee)Relative luminance 0.4143

Tints & shades

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

Harmonies

Complementary

Open in tool →

#fba35b

#5bfbf3 · #5b63fb

#fb5bb3 · #b3fb5b

Split-complementary

Open in tool →

#fb5b63 · #fbf35b

#f35bfb · #fba35b · #63fb5b

Contrast

#5bb3fb as textRatioAAAA largeAAAFix
Aaon white
2.26:1failfailfail
  • AA: use #0578d6 as the text (4.5:1)
  • AAA: use #04599f as the text (7.16:1)
  • AA: or shift the background to #404040 (4.58:1)
  • AAA: or shift the background to #212121 (7.12:1)
Aaon black
9.29:1passpasspassPasses 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 #5bb3fb as the background.

Brands using this color

Fonts for this mood

#5bb3fb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #5bb3fb
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 #5bb3fb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5bb3fb-9cadc4-df4e53-1f212d-e9f1f1?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