Color

#3f57cf

#3f57cf
hex#3f57cf
rgbrgb(63, 87, 207)
hslhsl(230, 60%, 53%)
oklchoklch(0.51 0.187 269.9)
Closest name: God of Rain (#4466cc)Relative luminance 0.1238

Tints & shades

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

Harmonies

Complementary

Open in tool →

#cfb73f

#3f9fcf · #6f3fcf

#cf3f57 · #57cf3f

Split-complementary

Open in tool →

#cf6f3f · #9fcf3f

#cf3f9f · #cfb73f · #3fcf6f

Contrast

#3f57cf as textRatioAAAA largeAAAFix
Aaon white
6.04:1passpassfail
  • AAA: use #324bc8 as the text (7.06:1)
Aaon black
3.48:1failpassfail
  • AA: use #586dd5 as the text (4.56:1)
  • AAA: use #8594e0 as the text (7.31:1)
  • AA: or shift the background to #e0e0e0 (4.58:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f57cf 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

#3f57cf reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f57cf
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 #3f57cf and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f57cf-9c9ec4-df814e-231f2d-e9eef1?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