Coloring Cells dependent upon their contents

Hey guys I was just wondering if there was a way to make excel look at every cell on every sheet, and if the cell is between 10 and 20 to color it yellow, and if it is greater than 20 color it red. Doing this for every sheet in a workbook would be the best possible way to do this for me, because i think it would be the fastest way as well. If you want/need an example let me know!

it did, I researched a little more after the fact, and I found conditional formatting to work very nicely in fact.