Color

#378cc8

#378cc8
hex#378cc8
rgbrgb(55, 140, 200)
hslhsl(205, 57%, 50%)
oklchoklch(0.616 0.122 243.2)
Closest name: steelblue (#4682b4)Relative luminance 0.2374

Colors that go with #378cc8

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 →

#c87337

#37c8bc · #3743c8

#c8378c · #8cc837

Split-complementary

Open in tool →

#c83743 · #c8bc37

#bc37c8 · #c87337 · #43c837

Contrast

#378cc8 as textRatioAAAA largeAAAFix
Aaon white
3.65:1failpassfail
  • AA: use #307bb0 as the text (4.58:1)
  • AAA: use #245c84 as the text (7.15:1)
  • AA: or shift the background to #1f1f1f (4.51:1)
Aaon black
5.75:1passpassfail
  • AAA: use #539cd0 as the text (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #378cc8 as the background.

Brands using this color

Fonts for this mood

#378cc8 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #378cc8
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 #378cc8 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/378cc8-9cafc4-df4e58-1f212d-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