Color

#3487df

#3487df
hex#3487df
rgbrgb(52, 135, 223)
hslhsl(211, 73%, 54%)
oklchoklch(0.617 0.155 252.8)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2339

Colors that go with #3487df

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 →

#df8d34

#34dcdf · #3734df

#df3487 · #87df34

Split-complementary

Open in tool →

#df3734 · #dcdf34

#df34dc · #df8d34 · #34df37

Contrast

#3487df as textRatioAAAA largeAAAFix
Aaon white
3.7:1failpassfail
  • AA: use #2177d4 as the text (4.51:1)
  • AAA: use #18579a as the text (7.32:1)
  • AA: or shift the background to #1c1c1c (4.61:1)
Aaon black
5.68:1passpassfail
  • AAA: use #5399e4 as the text (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3487df as the background.

Brands using this color

Fonts for this mood

#3487df reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3487df
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 #3487df and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3487df-9cabc4-df534e-1f202d-e9f1f1?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