Painting - Changing Latex Paint Color

I try to buy only the amount of paint I need for a project. But I tend to end up with more than less than I need. This of course it good and bad. Is there any way I can change the color of the left over paint myself. For example I have some paint left over that is a light orange sherbert color, could I change it to a purple my self? I also have some white left over.

It is always good to have paint left over from a job. That way you know that you had enough for your entire task. Assuming that you are talking about a latex paint, I would say that if you are a novice at painting and knowing the makeup of paint, there is not much that you can do about changing the color of the paint that you have. If you have a friend at a paint store, you could ask him/her to use the colorants that he/she has that are made for use with waterbased paints to change the color of what you have. Also, most latexes are compatable with each other, although not always, and you could mix a few different colors together. Doing this is risky. You do not know if you have the application properties that you like and you do know if the color will remain the same over a long period of time. My advice is to take the leftover paint to a recycling center and give it away.