Color

#427cf0

#427cf0
hex#427cf0
rgbrgb(66, 124, 240)
hslhsl(220, 85%, 60%)
oklchoklch(0.609 0.185 262.4)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2186

Colors that go with #427cf0

Charcoal, Crimson and Copper 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 →

#f0b642

#42d3f0 · #5f42f0

#f0427c · #7cf042

Split-complementary

Open in tool →

#f05f42 · #d3f042

#f042d3 · #f0b642 · #42f05f

Contrast

#427cf0 as textRatioAAAA largeAAAFix
Aaon white
3.91:1failpassfail
  • AA: use #2f6fee as the text (4.54:1)
  • AAA: use #104dc6 as the text (7.24:1)
  • AA: or shift the background to #171717 (4.59:1)
Aaon black
5.37:1passpassfail
  • AAA: use #6896f3 as the text (7.25:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #427cf0 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#427cf0 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #427cf0
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 #427cf0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/427cf0-9ca5c4-df694e-211f2d-e9f0f1?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