I know this one has been solved but I am encountering a similar issue I am going back in forth with this I pretty sure that I am just missing it by a little. I am trying to do this one by 180 days.

Yellow= after 150 days I was using =TODAY()+150
Red= after 180 days I was using =TODAY()+180
Green= between date taken and 150 days
Red= If blank

I have only played with the yellow and red right now I can't get them right I have messed with them a little.