Sum of Cells by Fill Color

Hello! I am a new member and this is my first post. I am using MSExcel 2003 on a Windows XP-PRO SP3 operating system.

I use Excel to keep track of my monthly corporate expense charges. Some of these charges are made with a credit card and others are made in cash. I use two different fill colors in the cells, one for credit card purchases and the other for cash.

Is there any way to have Excel total the cells based on fill color?

Thank you for any tips you can offer.