Color

#428cd1

#428cd1
hex#428cd1
rgbrgb(66, 140, 209)
hslhsl(209, 61%, 54%)
oklchoklch(0.625 0.128 249.2)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2452

Tints & shades

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

Harmonies

Complementary

Open in tool →

#d18742

#42d1cf · #4245d1

#d1428c · #8cd142

Split-complementary

Open in tool →

#d14245 · #d1cf42

#cf42d1 · #d18742 · #45d142

Contrast

#428cd1 as textRatioAAAA largeAAAFix
Aaon white
3.56:1failpassfail
  • AA: use #2e78bd as the text (4.63:1)
  • AAA: use #235b90 as the text (7.07:1)
  • AA: or shift the background to #212121 (4.53:1)
Aaon black
5.9:1passpassfail
  • AAA: use #5b9bd7 as the text (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #428cd1 as the background.

Brands using this color

Fonts for this mood

#428cd1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #428cd1
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 #428cd1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/428cd1-9cacc4-df4e4e-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