I agree with you Paultal as well as with SandraT.
If a pink horse is savage, what can we expect from a pink pig; your grand pa was d...right!
Spanish colonizers brought the arabian pink horse, don't know why, because they didn't use them for the army, as horses had to have a uniform "capa" coat(?) for their different squads.
If you yahoo or google to "refranes mexicanos" they quote them but don't explain. If you ask ganaderos mexicanos, by their blogs, they will start to
quarrel. So, why not ask a specialist (Herón Pérez Martinez, about "horses and women sayings") from "el Colegio de Michoacan ", & don' forgétotelme the final conclusions!:
http://redalyc.uaemex.mx/redalyc/pdf/137/13710407.pdf