I rejected a white model Y in CA on saturday due to paint mismatch. My issue was the front bumper having a yellow tint to it. I spoke with the delivery manager and he said the front and rear bumper are made of PVC where the rest of the car is Aluminum. Therefore they undergo a different paint process. Sometimes the paint on the bumpers comes out slightly different due to this. He said model 3 has similar issues and they carried spare bumpers to replace as needed but for model Y they do not have spares yet. I do have a photo I can upload for those of you that are interested (photo does not do justice to in person variation).