Animated Spots Chicken Pox How Would I Use Paint Or Gimp To Mass Edit 100 Pictures With A Few Clicks Of The Mouse?

How would I use paint or gimp to mass edit 100 pictures with a few clicks of the mouse? - animated spots chicken pox

I need to paint or use gimp to mass edit 100 pictures with just a few mouse clicks. In other words, if I were the color in Figure 1, which is also this place in another image change. This is a moving picture, and all have the same size. Thanks in advance!

BTW: Please do not say Photoshop. I did not know, and I have no money for it.