Color

#428fe0

#428fe0
hex#428fe0
rgbrgb(66, 143, 224)
hslhsl(211, 72%, 57%)
oklchoklch(0.64 0.144 252)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2618

Colors that go with #428fe0

Charcoal, Copper 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 →

#e09442

#42dee0 · #4542e0

#e0428f · #8fe042

Split-complementary

Open in tool →

#e04542 · #dee042

#e042de · #e09442 · #42e045

Contrast

#428fe0 as textRatioAAAA largeAAAFix
Aaon white
3.37:1failpassfail
  • AA: use #2277d3 as the text (4.52:1)
  • AAA: use #19579a as the text (7.31:1)
  • AA: or shift the background to #242424 (4.61:1)
Aaon black
6.24:1passpassfail
  • AAA: use #5499e3 as the text (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #428fe0 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#428fe0 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #428fe0
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 #428fe0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/428fe0-9cabc4-df534e-1f202d-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