I've had the white silicone and it wiped clean easily. Silicone is much better when it comes to staining. Think of all the many cooking utensils and baking pans made out of silicone. They don't stain. I had the white silicone and used it daily for over 6 months with no discoloration or staining. Carried it in a purse and in jeans pocket from time to time.How is the white holding up? I've had other white TPU cases that discolor quickly, especially because of my jeans.
On the other hand - light colored TPU picks up stains easily and will not come clean. The physical properties of the TPU allow it to pick up discoloration quickly but will not release the staining.