Color

#428bb8

#428bb8
hex#428bb8
rgbrgb(66, 139, 184)
hslhsl(203, 47%, 49%)
oklchoklch(0.609 0.1 238.5)
Closest name: steelblue (#4682b4)Relative luminance 0.2308

Colors that go with #428bb8

Charcoal, Copper and Royal Blue 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 →

#b86f42

#42b8aa · #4250b8

#b8428b · #8bb842

Split-complementary

Open in tool →

#b84250 · #b8aa42

#aa42b8 · #b86f42 · #50b842

Contrast

#428bb8 as textRatioAAAA largeAAAFix
Aaon white
3.74:1failpassfail
  • AA: use #3b7da5 as the text (4.5:1)
  • AAA: use #2d5d7c as the text (7.07:1)
  • AA: or shift the background to #1c1c1c (4.56:1)
Aaon black
5.62:1passpassfail
  • AAA: use #5e9dc5 as the text (7.1:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #428bb8 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

#428bb8 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #428bb8
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 #428bb8 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/428bb8-9cb0c4-df4e5d-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