Background Color

* The two main advantages for using CSS in web design are firstly that pages are easy to update and change, and secondly that you can apply a background color to more than just the few elements you can in HTML.
* If you place the declaration block background-color:#000; inside a body selector the whole of the body background will change, however if you place it inside a 'p' selector then only the background of that paragraph will change colour.
* NB: the background colour will stretch all the way across the screen as the p tag is a block element, however it will not effect the margin of the element.
* The default colour for an element is transparent.
* The colour values are usually defined as a hexadecimal value, e.g. #FF00FF - the first pair of digits relating to red, the second two relating to green and the third pair to blue (if there are only 3 digits then each digit is duplicated).
* Can also specify the background colour using RGB values, e.g.
background-color:rgb(18%, 25%, 70%);
background-color:rgb(200, 150, 50);
* The integer range is from 0 to 256.
* Can also use keywords to represent the values but this is not recommended as firstly the colours that support the keywords vary from browser to browser, and secondly because they are disallowed in the W3C accessability standards.