Blue Color Code: #0000FF, RGB, HSL & CMYK

Blue color values

HEX #0000FF

HEX (shorthand) #00F

RGB rgb(0, 0, 255)

HSL hsl(240, 100%, 50%)

HSV 240, 100%, 100%

HWB hwb(240 0% 0%)

CMYK 100%, 100%, 0%, 0%

Decimal 255

CSS keyword blue

50%HSL lightness (medium)

100%HSL saturation (vivid)

240°Hue angle (blue)

0.072Relative luminance

CMYK is a standard screen-to-print conversion. Printed results depend on inks, paper and color profiles.

What is Blue?

Blue is one of the named colors defined by the CSS Color specifications (keyword “blue”), so every modern browser understands it without a hex code.

Its hue angle of 240° places it in the blue part of the color wheel, with 100% saturation (vivid) and 50% lightness (medium). It is a cool color.

Compared with the other blue colors in the Aqeeb Studio library, it is lighter than 56% of them and more saturated than 87% of them.

Its relative luminance is 0.072, which makes it a dark color. That is below the 0.179 crossover point at which black and white text have equal contrast, so white text has the advantage. The HEX code can also be written in the shorthand form #00F.

Blue counts as a dark color: its HSL lightness is 50% and its relative luminance is 0.072. White text reads comfortably on it (8.59:1 contrast).

Text contrast on Blue

WCAG contrast of white and black text on Blue
Text	Preview	Ratio	AA normal	AA large	AAA normal	AAA large
White text	Sample text	8.59:1 Excellent	Pass	Pass	Pass	Pass
Black text	Sample text	2.44:1 Poor	Fail	Fail	Fail	Fail

Ratios use the WCAG 2 formula and are truncated, never rounded up. Test any pair with the contrast checker.

Colors that go with Blue

Complementary color

Complementary colors sit directly opposite each other on the color wheel (180° apart). They give the strongest hue contrast, which suits calls to action and accents.

Yellow#FFFF00

Analogous colors

Analogous colors are neighbors on the wheel, 30° either side of the base hue. They blend smoothly and are easy to combine in backgrounds, gradients and illustrations.

≈ Cerulean Blue#0080FF ≈ Vivid Purple#8000FF

Triadic colors

A triadic scheme uses three hues spaced 120° apart. It is lively yet balanced, and works best when one color leads and the other two act as accents.

Red#FF0000 Lime#00FF00

Split-complementary colors

Split-complementary keeps the base color and uses the two colors on either side of its complement (150° and 210°). The contrast is strong but gentler than a direct complement.

≈ Pumpkin Orange#FF8000 ≈ Chartreuse#80FF00

Tetradic colors

A tetradic (rectangle) scheme combines two complementary pairs at 0°, 60°, 180° and 240°. It offers variety but needs one dominant color to stay balanced.

Magenta#FF00FF Yellow#FFFF00 Lime#00FF00

Monochromatic variants

Monochromatic variants keep the same hue and saturation and only change lightness, which makes them dependable for UI scales and subtle layered designs.

#000070#000070

#0000B8#0000B8

#0000FF#0000FF

#4747FF#4747FF

#8F8FFF#8F8FFF

A “≈” before a name means the exact harmony color has no named match, so the link goes to the closest named color.

Tints and shades of Blue

Lighter tints (mixed with white)

Darker shades (mixed with black)

Select any swatch to copy its HEX code. Build longer scales with the tints and shades tool.

Strong Blue#0C06F7 Rich Blue#021BF9 Pure Blue#0203E2 Vivid Blue#152EFF Light Royal Blue#3A2EFE Ultramarine Blue#1805DB Medium Blue#0000CD Vibrant Blue#0339F8

Where to use Blue

Button, banner and badge backgrounds with white text (8.59:1 contrast)
Accents that need to stand out: call-to-action buttons, charts and illustrations
Headers and navigation bars
Charts and dashboards
Links, buttons and primary interface accents
Corporate, finance and software branding

Blue appears in these curated palettes: Pop Art (Vibrant Color Palettes).

Use Blue in CSS

:root {
  --color-blue: #0000FF;
}

.element {
  color: var(--color-blue);
  background-color: #0000FF;
  border: 2px solid #0000FF;
}

Questions about Blue

What is the HEX code for Blue?

Blue is #0000FF. The shorthand form #00F is equivalent.

What is the RGB value of Blue?

The RGB value of Blue is 0, 0, 255: 0 red, 0 green and 255 blue on a 0–255 scale, written rgb(0, 0, 255) in CSS.

What is the HSL value of Blue?

The HSL value of Blue is 240°, 100%, 50% (hue, saturation, lightness), written hsl(240, 100%, 50%) in CSS.

What is the CMYK value of Blue?

A standard conversion gives about C 100%, M 100%, Y 0%, K 0%. Real print results depend on the inks, paper and color profile, so treat CMYK here as a reference value.

Is Blue a light or dark color?

Blue counts as a dark color: its HSL lightness is 50% and its relative luminance is 0.072. White text reads comfortably on it (8.59:1 contrast).

How does Blue look with white text?

White text on Blue has a contrast ratio of 8.59:1, rated Excellent. It meets WCAG AA for normal text.

How does Blue look with black text?

Black text on Blue has a contrast ratio of 2.44:1, rated Poor. It falls below the WCAG minimum for text.

What colors go well with Blue?

Yellow is its complementary color, and Cerulean Blue sits beside it as an analogous color. Lighter and darker variants of the same hue also work well for monochromatic palettes.

Where can Blue be used?

It suits button, banner and badge backgrounds with white text (8.59:1 contrast); accents that need to stand out: call-to-action buttons, charts and illustrations; headers and navigation bars.

How do I use Blue in CSS?

Use color: #0000FF; for text, background-color: #0000FF; for fills, or define a custom property such as --color-blue: #0000FF; and reuse it with var(--color-blue).

About this color page

CSS named color (W3C CSS Color Module). Values are calculated from the HEX code; color names are labels, not trademarks or standards unless stated. Screens render colors differently, so always check important colors on your own device. See the disclaimer.

Blue Color Code: #0000FF