Color

#42ffff

#42ffff
hex#42ffff
rgbrgb(66, 255, 255)
hslhsl(180, 100%, 63%)
oklchoklch(0.911 0.144 194.9)
Closest name: aqua (#00ffff)Relative luminance 0.799

Colors that go with #42ffff

Charcoal, Deep Sky Blue and Taupe lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ff4242

#42ffa1 · #42a1ff

#ff42ff · #ffff42

Split-complementary

Open in tool →

#ff42a1 · #ffa142

#a142ff · #ff4242 · #a1ff42

Contrast

#42ffff as textRatioAAAA largeAAAFix
Aaon white
1.24:1failfailfail
  • AA: use #008080 as the text (4.77:1)
  • AAA: use #006161 as the text (7.29:1)
  • AA: or shift the background to #666666 (4.64:1)
  • AAA: or shift the background to #4a4a4a (7.17:1)
Aaon black
16.98:1passpasspassPasses 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 #42ffff as the background.

Brands using this color

Fonts for this mood

#42ffff reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #42ffff
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

›analyze #42ffff and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/42ffff-a2bbbe-d45994-1f272d-e9f1ed?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