Lol indeed! To a degree I find many Smokey cremes and brown cremes to be able to tell if they're silver or not also, though not nearly as easily as Perlinos (:
Not all perlinos are silver though, which I found out recently too. I was breeding for a quest and driving myself crazy with this stallion. Then I gene tested him and found out he's not silver.
-HEE Click- Every vitiligo I've ever encountered has the same pattern; they always have the spot on the ear, the cluster at the hindquarters, shoulder and across their face. The ear spot is the best way to tell early on (: