For my dear BFP,
Depending on what camera you have, all factors can play a critical role in the colors popping in your pic.
I went out for a walk and was eyeing the same tree. I took a few shots and got the effect I think you are talking about -- lighter sky, deeper flower color -- and I got it by playing with the shutter speed. That's my area that I always play with.
I have a Nikon D80 with a ProMaster lens, 17-50mm.
Keep playing around with yours until you get it. The colors will come!