Learn CSS tricks for beginner : Colours

The following values, to specify full-on as red-as-red-can-be, all produce the same result:

• red
• rgb(255,0,0)
• rgb(100%,0%,0%)
• #ff0000
• #f00

Predefined color names include aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, orange, purple,red, silver, teal, white, and yellow. transparent is also a valid value.

With the possible exception of black and white, color names have limited use in a modern, well-designed web sites because they are so specific and limiting.

The three values in the RGB value are from 0 to 255, 0 being the lowest level (no red, for example), 255 being the highest level (full red, for example). These values can also be a percentage.

Hexadecimal (previously and more accurately known as “sexadecimal”) is a base-16 number system. We are generally used to the decimal number system (base-10, from 0 to 9), but hexadecimal has 16 digits, from 0 to f.

The hex number is prefixed with a hash character (#) and can be three or six digits in length. Basically, the three-digit version is a compressed version of the six-digit (#ff0000 becomes #f00, #cc9966 becomes #c96, etc.). The three-digit version is easier to decipher (the first digit, like the first value in RGB, is red, the second green and the third blue) but the six-digit version gives you more control over the exact color.

CSS3, the latest version of CSS, also allows you to define HSL colors - hue, saturation and lightness. More on this, along with semi-transparent colors, can be found in the CSS Advanced Tutorial.

color and background-color

Colors can be applied by using color and background-color (note that this must be the American English “color” and not “colour”).

A blue background and yellow text could look like this:

h1 {
    color: yellow;
    background-color: blue;
}

These colors might be a little too harsh, so you could change the code of your CSS file for slightly different shades:

body {
    font-size: 14px;
    color: navy;
}
h1 {
    color: #ffc;
    background-color: #009;
}

Save the CSS file and refresh your browser. You will see the colors of the first heading (the h1 element) have changed to yellow and blue.

You can apply the color and background-color properties to most HTML elements, including body, which will change the colors of the page and everything in it.