CSS Colors
CSS supports 140+ color names, HEX values, RGB values, RGBA
values, HSL values, HSLA values, and opacity.
RGBA Colors
RGBA color values are an
extension of RGB color values with an alpha channel - which specifies the
opacity for a color.
An RGBA color value is
specified with: rgba(red, green, blue, alpha). The alpha parameter is a number
between 0.0 (fully transparent) and 1.0 (fully opaque).
rgba(255, 0, 0, 0.2);
rgba(255, 0, 0, 0.4);
rgba(255, 0, 0, 0.6);
rgba(255, 0, 0, 0.8);
The following example defines different RGBA
colors:
Example
#p1 {background-color: rgba(255, 0, 0, 0.3);} /* red with opacity */
#p2 {background-color: rgba(0, 255, 0, 0.3);} /* green with opacity */
#p3 {background-color: rgba(0, 0, 255, 0.3);} /* blue with opacity */
HSL Colors
HSL stands for Hue,
Saturation and Lightness.
An HSL color value is
specified with: hsl(hue, saturation, lightness).
- Hue
is a degree on the color wheel (from 0 to 360):
- 0
(or 360) is red
- 120
is green
- 240
is blue
- Saturation
is a percentage value: 100% is the full color.
- Lightness
is also a percentage; 0% is dark (black) and 100% is white.
hsl(0, 100%, 30%);
hsl(0, 100%, 50%);
hsl(0, 100%, 70%);
hsl(0, 100%, 90%);
The following example defines different HSL
colors:
Example
#p1 {background-color: hsl(120, 100%, 50%);} /* green */
#p2 {background-color: hsl(120, 100%, 75%);} /* light green */
#p3 {background-color: hsl(120, 100%, 25%);} /* dark green */
#p4 {background-color: hsl(120, 60%, 70%);} /* pastel green */
HSLA Colors
HSLA color values are an
extension of HSL color values with an alpha channel - which specifies the
opacity for a color.
An HSLA color value is
specified with: hsla(hue, saturation, lightness, alpha), where the alpha
parameter defines the opacity. The alpha parameter is a number between 0.0
(fully transparent) and 1.0 (fully opaque).
hsla(0, 100%, 30%, 0.3);
hsla(0, 100%, 50%, 0.3);
hsla(0, 100%, 70%, 0.3);
hsla(0, 100%, 90%, 0.3);
The following example defines different HSLA
colors:
Example
#p1 {background-color: hsla(120, 100%, 50%, 0.3);} /* green with opacity */
#p2 {background-color: hsla(120, 100%, 75%, 0.3);} /* light green with opacity
*/
#p3 {background-color: hsla(120, 100%, 25%, 0.3);} /* dark green with opacity
*/
#p4 {background-color: hsla(120, 60%, 70%, 0.3);} /* pastel green with
opacity */
Opacity
The CSS opacity property
sets the opacity for the whole element (both background color and text will be
opaque/transparent).
The opacity property
value must be a number between 0.0 (fully transparent) and 1.0 (fully opaque).
rgb(255, 0, 0);opacity:0.2;
rgb(255, 0, 0);opacity:0.4;
rgb(255, 0, 0);opacity:0.6;
rgb(255, 0, 0);opacity:0.8;
Notice that the text above will also be
transparent/opaque!
The following example shows
different elements with opacity:
Example
#p1 {background-color:rgb(255,0,0);opacity:0.6;} /* red with opacity */
#p2 {background-color:rgb(0,255,0);opacity:0.6;} /* green with opacity */
#p3 {background-color:rgb(0,0,255);opacity:0.6;} /* blue with opacity */