What can causes the different color in the colas. Its the same Plant.

I'm thinking this just may be your plant telling you it's time.... The lower bud sites will always be "healthier looking" i.e., still growing, still developing when the top bud sites might need harvesting. If you refer to my Tangerine Dream green again, you'll see I had to harvest in stages - the tops were ready, leaves yellowing, trichs turning amber, but the bottom buds still needed more time and so I gave it to them. Nothing wrong with that! Quite frankly, I was happy not to have to trim the entire thing all at one time. My personal belief is that after 65 days in flower, she just might be ready for her top to be harvested... have you been checking the trichomes? Let THEM tell you what's going on... Good luck! The grow looks amazing!