Color

#397cef

#397cef
hex#397cef
rgbrgb(57, 124, 239)
hslhsl(218, 85%, 58%)
oklchoklch(0.605 0.186 260.5)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2152

Tints & shades

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

Harmonies

Complementary

Open in tool →

#efac39

#39d7ef · #5139ef

#ef397c · #7cef39

Split-complementary

Open in tool →

#ef5139 · #d7ef39

#ef39d7 · #efac39 · #39ef51

Contrast

#397cef as textRatioAAAA largeAAAFix
Aaon white
3.96:1failpassfail
  • AA: use #266fed as the text (4.59:1)
  • AAA: use #1051c1 as the text (7.07:1)
  • AA: or shift the background to #171717 (4.53:1)
Aaon black
5.3:1passpassfail
  • AAA: use #5f95f2 as the text (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #397cef as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#397cef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #397cef
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #397cef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/397cef-9ca6c4-df644e-201f2d-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