White hooves are no softer than black ones. It is a myth. The color difference generally is due to the hair color of the leg on most horses. My mare has two white (one in front and one in back) and two black – no difference in wear and tear, trims, etc. The reasons so many people think the white ones are softer are that bruising is easier to see, and since many people wash white legs more often, that can affect the hoof.
That said, if your farrier or vet thinks you should use boots, go for it.
It is never the horse's fault