Colour is a big subject. As soon as you add more than one colour to a page, you make the other colours look different. Some colours are complementary, and some just look terrible together. On the web, though, you should usually avoid using too many colours on one page - even if they are complementary, it will look garish. For the web, hue is more important: the best way to create a colour scheme is to use black, white, and various shades of one colour. You have to consider the brightness and intensity of your colours, to make sure you're not overdoing things. One of the easiest mistakes to make is to use the built-in CSS colour words instead of creating colour codes - the colour words should generally be avoided, because they're just too intense.

You can create all sorts of illusions with the amount of space you put between your objects, and where you put it: design is often as much knowing where to put something as it is knowing what to put there. If you make things overlap, or example, the covered things appear to be at the 'back' while the uncovered ones are at the 'front'. Lots More. This is the briefest of brief overviews, because graphic design is a surprisingly large subject, and one that's changing all the time. If you want to get properly up to speed, it's worth buying a book, or even taking an evening course at your local college - you won't regret it.