Color

#3f7be9

#3f7be9
hex#3f7be9
rgbrgb(63, 123, 233)
hslhsl(219, 79%, 58%)
oklchoklch(0.601 0.178 261.3)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2111

Tints & shades

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

Harmonies

Complementary

Open in tool →

#e9ad3f

#3fcfe9 · #593fe9

#e93f7b · #7be93f

Split-complementary

Open in tool →

#e9593f · #cfe93f

#e93fcf · #e9ad3f · #3fe959

Contrast

#3f7be9 as textRatioAAAA largeAAAFix
Aaon white
4.02:1failpassfail
  • AA: use #3271e7 as the text (4.51:1)
  • AAA: use #1650bb as the text (7.24:1)
  • AA: or shift the background to #141414 (4.58:1)
Aaon black
5.22:1passpassfail

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f7be9 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

#3f7be9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f7be9
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 #3f7be9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f7be9-9ca5c4-df664e-211f2d-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