Color

#399bb1

#399bb1
hex#399bb1
rgbrgb(57, 155, 177)
hslhsl(191, 51%, 46%)
oklchoklch(0.642 0.095 215.5)
Closest name: Blue Moon (#3992a8)Relative luminance 0.2749

Colors that go with #399bb1

Charcoal, Orange Red 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.

Real palettes that use #399bb1

Tints & shades

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

Harmonies

Complementary

Open in tool →

#b14f39

#39b18b · #395fb1

#b1399b · #9bb139

Split-complementary

Open in tool →

#b1395f · #b18b39

#8b39b1 · #b14f39 · #5fb139

Contrast

#399bb1 as textRatioAAAA largeAAAFix
Aaon white
3.23:1failpassfail
  • AA: use #2f8092 as the text (4.54:1)
  • AAA: use #235e6c as the text (7.27:1)
  • AA: or shift the background to #292929 (4.5:1)
Aaon black
6.5:1passpassfail
  • AAA: use #3ca2b9 as the text (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #399bb1 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

#399bb1 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #399bb1
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 #399bb1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/399bb1-a2b6be-df4e7a-1f252d-e9f1ef?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