CSS named color

Blue #0000FF

Blue is a vivid blue with the hex code #0000FF, which converts to rgb(0, 0, 255). Open #0000FF in the converter to tweak it.

Blue color values

How #0000FF converts to RGB

Split the hex code into three pairs and read each pair as a base-16 number: 00 → 0, 00 → 0, FF → 255. That gives rgb(0, 0, 255). The step-by-step guide explains the math.

Shades of Blue

Mixed toward black in 10% steps. Click a swatch to copy its hex.

Tints of Blue

Mixed toward white in 10% steps.

Color harmonies

Hue rotations of Blue on the HSL color wheel, keeping saturation and lightness fixed. The color harmony guide explains when each scheme works.

Complementary

Analogous

Split-complementary

Triadic

Tetradic (square)

Contrast and accessibility

Use white text on a blue background. Test any other pair in the contrast checker; thresholds are explained in the WCAG contrast guide.

Use Blue in CSS

.element {
  color: blue;                         /* keyword */
  background-color: #0000FF;            /* hex */
  border-color: rgb(0 0 255 / 50%);    /* 50% transparent */
}

Need it semi-transparent? Append an alpha byte: #0000FF80 is Blue at 50% opacity. See RGBA & transparency.

Similar named colors

FAQ

What is the HEX code for Blue?

The CSS named color blue is #0000FF in hexadecimal. In CSS you can write color: blue; or color: #0000FF; — both produce the same pixel.

What is Blue in RGB?

Blue is rgb(0, 0, 255): red 0, green 0, blue 255 on the 0–255 scale. As normalized 0–1 floats that is (0, 0, 1).

Is white or black text more readable on Blue?

White text is more readable. White on #0000FF has a contrast ratio of 8.59:1 (AAA), black on #0000FF has 2.44:1 (Fail). WCAG AA needs 4.5:1 for normal text.