Color

#15b5f4

#15b5f4
hex#15b5f4
rgbrgb(21, 181, 244)
hslhsl(197, 91%, 52%)
oklchoklch(0.728 0.147 233.2)
Closest name: Blue Bikini (#00bbee)Relative luminance 0.3974

Tints & shades

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

Harmonies

Complementary

Open in tool →

#f45415

#15f4c4 · #1545f4

#f415b5 · #b5f415

Split-complementary

Open in tool →

#f41545 · #f4c415

#c415f4 · #f45415 · #45f415

Contrast

#15b5f4 as textRatioAAAA largeAAAFix
Aaon white
2.35:1failfailfail
  • AA: use #087caa as the text (4.69:1)
  • AAA: use #065c7f as the text (7.38:1)
  • AA: or shift the background to #3d3d3d (4.63:1)
  • AAA: or shift the background to #1f1f1f (7.02:1)
Aaon black
8.95:1passpasspassPasses 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 #15b5f4 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#15b5f4 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #15b5f4
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 #15b5f4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/15b5f4-9cb4c4-df4e6b-1f232d-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