RGB and RGBA Colors

RGB Color Values

An RGB color value represents RED, GREEN, and BLUE light sources.

In HTML, a color can be specified as an RGB value, using this formula:

rgb(red, green, blue)

Each parameter (red, green, and blue) defines the intensity of the color with a value between 0 and 255. This means that there are 256 x 256 x 256 = 16,777,216 possible colors!

For example:

rgb(255, 0, 0) is displayed as red, because red is set to its highest value (255), and the other two (green and blue) are set to 0.
rgb(0, 255, 0) is displayed as green, because green is set to its highest value (255), and the other two (red and blue) are set to 0.
rgb(0, 0, 0) displays black, as all color parameters are 0.
rgb(255, 255, 255) displays white, as all color parameters are set to 255.

Examples


<p style="background-color:rgb(255, 0, 0);"> MSK </p>
<p style="background-color:rgb(0, 0, 255);"> MSK </p>
<p style="background-color:rgb(60, 179, 113);"> MSK </p>
<p style="background-color:rgb(238, 130, 238);"> MSK </p>
<p style="background-color:rgb(255, 165, 0);"> MSK </p>
<p style="background-color:rgb(106, 90, 205);"> MSK </p>

Shades of Gray

Shades of gray are often defined using equal values for all three parameters:

Examples


<p style="background-color:rgb(60, 60, 60); color:white;"> MSK </p>
<p style="background-color:rgb(100, 100, 100); color:white;"> MSK </p>
<p style="background-color:rgb(140, 140, 140); color:white;"> MSK </p>
<p style="background-color:rgb(180, 180, 180); "> MSK </p>
<p style="background-color:rgb(200, 200, 200); "> MSK </p>
<p style="background-color:rgb(240, 240, 240); "> MSK </p>

RGBA Color Values

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 (not transparent at all).

Experiment by mixing the RGBA values below:


<p style="background-color:rgba(255, 99, 71, 0);"> MSK </p>
<p style="background-color:rgba(255, 99, 71, 0.2);"> MSK </p>
<p style="background-color:rgba(255, 99, 71, 0.4);"> MSK </p>
<p style="background-color:rgba(255, 99, 71, 0.6);"> MSK </p>
<p style="background-color:rgba(255, 99, 71, 0.8);"> MSK </p>
<p style="background-color:rgba(255, 99, 71, 1);"> MSK </p>


<div class="box" style="background-color: yellow; width: 300px; height: 80px;">
    <h3 style="background-color: rgba(0, 0, 0, 0.3); width: 100px; height: 70px;">Hello</h3>
</div>