Sorry about the delay I was working this evening. This is really not as complex as it looks. There are two circles nodes 1-12 with centers nodes 1, 6 and 12, 6. The fade in and out is controlled by nodes 19, 20 and 22-24. Nodes 13, 14, 16, and 18 invert and adjust the circles for the desired effect. That leaves nodes 21 which add the circles together and 17 to multiply the fade equations. The color math node subtracts green to get the red blush. Please build and open the previews this entire equation is done in grey (between zero and one), so it is very easy to troubleshoot and understand.