Color

#42b1fa

#42b1fa
hex#42b1fa
rgbrgb(66, 177, 250)
hslhsl(204, 95%, 62%)
oklchoklch(0.73 0.145 241.8)
Closest name: Cerulean (#55aaee)Relative luminance 0.395

Colors that go with #42b1fa

Charcoal, Dark Orange and Amber 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 →

#fa8c42

#42fae8 · #4254fa

#fa42b1 · #b1fa42

Split-complementary

Open in tool →

#fa4254 · #fae842

#e842fa · #fa8c42 · #54fa42

Contrast

#42b1fa as textRatioAAAA largeAAAFix
Aaon white
2.36:1failfailfail
  • AA: use #0579c7 as the text (4.6:1)
  • AAA: use #045b95 as the text (7.15:1)
  • AA: or shift the background to #3d3d3d (4.6:1)
  • AAA: or shift the background to #1c1c1c (7.22:1)
Aaon black
8.9:1passpasspassPasses 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 #42b1fa as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#42b1fa reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #42b1fa
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 #42b1fa and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/42b1fa-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