Color

#3978ac

#3978ac
hex#3978ac
rgbrgb(57, 120, 172)
hslhsl(207, 50%, 45%)
oklchoklch(0.555 0.104 246.1)
Closest name: Blue Triumph (#4376ab)Relative luminance 0.1728

Colors that go with #3978ac

Charcoal, Sienna 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 →

#ac6d39

#39aca6 · #393fac

#ac3978 · #78ac39

Split-complementary

Open in tool →

#ac393f · #aca639

#a639ac · #ac6d39 · #3fac39

Contrast

#3978ac as textRatioAAAA largeAAAFix
Aaon white
4.71:1passpassfail
  • AAA: use #2b5b82 as the text (7.19:1)
Aaon black
4.46:1failpassfail
  • AA: use #3b7bb0 as the text (4.65:1)
  • AAA: use #629ccb as the text (7.14:1)
  • AA: or shift the background to #fafafa (4.51:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3978ac as the background.

Brands using this color

Fonts for this mood

#3978ac reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3978ac
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 #3978ac and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3978ac-9cadc4-df4e53-1f212d-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