You can use “Change to color” effect to make the same hue for all spheres (from purple to color you need). Maybe this is what you want, but probably some of them will be slightly darker or lighter than others.

You probably can’t just remove it. Because all the spheres are nothing else than only one pre-rendered movie. Your logo (or other image) is supposed to be “printed” directly on the big sphere in this template.

this is my problem, that’s pre rendered, because I want to remove only the big sphere in the center and see only the little ones