Color

#3f7be4

#3f7be4
hex#3f7be4
rgbrgb(63, 123, 228)
hslhsl(218, 75%, 57%)
oklchoklch(0.598 0.171 260.7)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2082

Colors that go with #3f7be4

Charcoal, Crimson and Copper 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 →

#e4a73f

#3fcee4 · #553fe4

#e43f7b · #7be43f

Split-complementary

Open in tool →

#e4553f · #cee43f

#e43fce · #e4a73f · #3fe455

Contrast

#3f7be4 as textRatioAAAA largeAAAFix
Aaon white
4.07:1failpassfail
  • AA: use #3272e2 as the text (4.53:1)
  • AAA: use #1a54b7 as the text (7.01:1)
  • AA: or shift the background to #141414 (4.53:1)
Aaon black
5.16:1passpassfail
  • AAA: use #6797e9 as the text (7.18:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f7be4 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

#3f7be4 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f7be4
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 #3f7be4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f7be4-9ca6c4-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