Will these still mix in well with the Preview Clone?
Anyone worried that the paint jobs on the different colored Clones might not be too great?

Good questions Chewy. I just got the three pack during the week. And right now, I'm comparing them to one of my preview Clone Troopers.
Obiviously, there's the cosmetic paint differences, with the Preview Clone Trooper being dirty, and the 3-Pack Clones being clean. Aside from that, one of the biggest differences? A slight paint difference on the helmet (on the mouth grill, and a ring around the top/back), backplate, and stomach sections of the armor. The preview Clones have some grey detail paint on those sections, while the 3-pack Clones are all white. I think they're still fairly interchangeable. But I think the clean Clone Troopers will fit in better in dioramas with the Clone Trooper Pilot and Clone Trooper (red trim) because those versions are also clean.