This pony is labeled on Pinterest as "Steely Dan, purebred crop-out Welsh pony." If the white is from one of the Splash genes, then I believe that's possible in Welsh ponies. I can't find any other info about him.
Palomino Welsh pony stallion. Palomino horses have gold-colored coat with a white or light cream colored mane and tail. The Palomino's coat can range from a light off-white shade to a deep shade of gold.