Although the monkey wears in silk, monkey it remains!!!
(You can’t make a silk purse out of a sow’s ear).
It is often used when someone pretends that has more class (upwards) or finer taste than the facts.
A person can wear very expensive clothes or drives luxury cars and then he/she opens his/her mouth and sounds vulgar or walks like an elephant pretending she is graceful.
They overdo protocol rules.
A “monkey”, as you probably know, is very similar to human beings. The expression “Aunque la mona se vista de seda, ¡¡¡mona se queda!!!” is normally used to mean that it is impossible to make something fine out of inferior or substandard material. The idiom is normally used in the negative. It is also possible to say, “La mona siempre es mona, incluso si viste de púrpura”
No matter how hard you try,you can’t!