Color

#3f8be9

#3f8be9
hex#3f8be9
rgbrgb(63, 139, 233)
hslhsl(213, 79%, 58%)
oklchoklch(0.635 0.16 255.3)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2541

Colors that go with #3f8be9

Charcoal, Amber and Blue 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 →

#e99c3f

#3fe0e9 · #483fe9

#e93f8b · #8be93f

Split-complementary

Open in tool →

#e9483f · #e0e93f

#e93fe0 · #e99c3f · #3fe948

Contrast

#3f8be9 as textRatioAAAA largeAAAFix
Aaon white
3.45:1failpassfail
  • AA: use #1a73e0 as the text (4.59:1)
  • AAA: use #1457a9 as the text (7.08:1)
  • AA: or shift the background to #212121 (4.66:1)
Aaon black
6.08:1passpassfail
  • AAA: use #5699eb as the text (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f8be9 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

#3f8be9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f8be9
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 #3f8be9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f8be9-9ca9c4-df584e-1f202d-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