I don't know anything about Mac's but all of my computers have come with a paint program or Photo Editing of some sort. Check your program files. Maybe under "accessories" or something like that. If you don't already have something, you can download one of the programs that the paint companies have such as Benjamin Moore. I think theirs is around $10 and totally worth it in my opinion. I use it ALL the time! Just beware that the colors on a virtual drawing aren't usually very accurate. They are only to give you an idea which direction to go when you're searching for paint samples to try. Good Luck!

Lindy