So you are trying to put together a web site. One aesthetic item you will need to consider is what colors to use. Colors have differing psychological meaning. If you are driving, seeing a red light in front of you ( or blue lights behind you ) will cause an emotional response. There are several web sites that deal with this topic.
Colors that look great in print may appear different on a particular computer. This has to do with the Gamma rays or something that the computer has. Older computers could only handle a small number (256) of colors denoted as 'web safe colors.'
The color produced is determined by the three color channels, namely Red, Green, and Blue. I know I swear in second grade I learned it was Red, Yellow and Green. Anyways, each channel can be increased to make a color more Blue or more Red, etc.
The volume control for each channel does not go from 1 to 10. That would be too easy. Instead, the degrees of color go from 0 to 9 and then from A to F. This gives a total of 16 options for each channel.
Each Channel is further divided into two digits, still using the 0-9 and A-F range.
Bright Red is produced by an RGB of FF0000. In other words, the Red Channel is at the maximum and the Green and Blue Channels are at a minimum. Bright Blue would similarly be produced by an RGB of 0000FF.
So within each channel you have 256 options ranging from 00 to FF. Why is this 256? Well, 0-9 and A-F produces 16 options. This is called a hexidecimal system. So the two digits would produce 16 times 16 options or 256. Not coincidentally, 256 happens to be 2 to the 8th power. And if you read enough computer books you know that computers speak in a base 2 language of bits and bytes.
So Red is FF0000, Blue is 0000FF, Green is 00FF00. Black (lack of any color) is 000000 and White (maximum of every color) is FFFFFF. Gray ( no color is predominant) is 666666 for a dark shade and cccccc for a light shade.
Purple (Red and Blue) is FF00FF, Aqua (Green and Blue) is 00FFFF, and finally Yellow ( Red? and Green?) is FFFF00. I know the yellow one still throws me off a little bit.
So a three level rainbow would look like this:
A 6 level rainbow would look like this:
A 12 level rainbow would look like this:
Finally the full rainbow would look like this:
Of course you can make the colors darker:
Or Lighter:
The total number of available colors is over one million. There are certain common colors that are hiding in between the ones I have illustrated.
When choosing a color scheme, keep a few things in mind. Dark fonts on a light back ground are the easiest to read. Always use a sufficient amount of contrast between the content on the page and the back ground so that your words can be read. Certain colors do cause a psychological response. Certain colors seem natural such as greens, browns, and yellow, while others may seem more mechanical and modern such as blue.
When combining colors you have several different options. You can always use white and black with other colors. Different shades of gray can also be used without a problem. You can be monochromatic and just use lighter and darker shades of the same color. You can several colors that are near each other on the rainbow. Be careful with this analogous strategy since it is easy to have a color clash if you move to far away from your base color. You can use the opposite or complimentary color. For instance a blue background with yellow writing is often used in advertising. If you use this strategy you might need to lighten one of the colors or make it less bright.