Color

#1f39ff

#1f39ff
hex#1f39ff
rgbrgb(31, 57, 255)
hslhsl(233, 100%, 56%)
oklchoklch(0.497 0.283 266.4)
Closest name: C64 Blue (#003aff)Relative luminance 0.1044

Colors that go with #1f39ff

Charcoal, Crimson and Cobalt 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 →

#ffe51f

#1fa9ff · #751fff

#ff1f39 · #39ff1f

Split-complementary

Open in tool →

#ff751f · #a9ff1f

#ff1fa9 · #ffe51f · #1fff75

Contrast

#1f39ff as textRatioAAAA largeAAAFix
Aaon white
6.8:1passpassfail
  • AAA: use #1a34ff as the text (7.05:1)
Aaon black
3.09:1failpassfail
  • AA: use #5266ff as the text (4.7:1)
  • AAA: use #808eff as the text (7.23:1)
  • AA: or shift the background to #d4d4d4 (4.59:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1f39ff as the background.

Brands using this color

Fonts for this mood

#1f39ff reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1f39ff
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 #1f39ff and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1f39ff-9c9cc4-df884e-241f2d-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