Enseñar el cobre

[poli]

I know it translates in English to show your true colors.
Does it always imply the negative?

[AngelicaDeAlquezar]

Yes, it is always negative.
It is used to say that someone pretended to be something they are not. Their true intentions or defects are shown by some act they committed. I think it comes from old falsified currency that were pieces of copper covered in a thin golden layer and they paid with them as if they were gold. A little scratch, and the copper core showed up.

- ¿Así que sólo querías dinero? Qué pronto enseñaste el cobre.
So you only wanted money? You showed soon your true intentions.
- Luego de que la denunciaron, la presidenta municipal mostró el cobre y amenazó a los periodistas.
After having been accused, the mayor showed her true colors and threatened the journalists.
- Yo siempre creí que Pedro era decente, pero anoche en la fiesta sacó el cobre y todos queríamos que se fuera.
I always thought of Pedro as a decent person, but last night he behaved so bad that we all wanted him to leave.

[pinosilano]

Originally Posted by AngelicaDeAlquezar

Yes, it is always negative.
It is used to say that someone pretended to be something they are not. Their true intentions or defects are shown by some act they committed. I think it comes from old falsified currency that were pieces of copper covered in a thin golden layer and they paid with them as if they were gold. A little scratch, and the copper core showed up.

Según ===>

https://heraldodemexico.com.mx/tende...on-268566.html

se trata de una locución Mexicana. Nunca la había escuchado ni leído
Conosco bien "mostrar la hilacha" que es muy parecido y tiene origen judío, según ===>

https://www.semanariohebreojai.com/articulo/376

[AngelicaDeAlquezar]

Ah, no conocía la segunda expresión, pero el significado es claro. Por razones de su origen, me quedo con "mostrar el cobre".

[pinosilano]

Originally Posted by AngelicaDeAlquezar

Ah, no conocía la segunda expresión, pero el significado es claro. Por razones de su origen, me quedo con "mostrar el cobre".

En cambio, yo usaré el mexicanismo, ya que me gusta partecipar a las reuniones "12Steps" de México, Colombia, Caribe, Venezuela, Centroamérica.
En tales reuniones usan un lenguaje muy informal que poco a poco voy entendiendo.

[AngelicaDeAlquezar]

El lenguaje coloquial puede ser incomprensible, pero en contexto es menos difícil.

[poli]

It just occurred to me that enseñar el cobre is similar to the English test one's mettle. The Spanish phrase indicates a kind of moral failure, and the English phrase is more of a proof of character.

Do you know of a Spanish equivalent to show true colors in a positive vain?

[AngelicaDeAlquezar]

Probably "mostrar de qué está hecho alguien". This means that someone has been put to a test where they must show their capabilities, for good or for bad.
- En el último partido el equipo tiene que mostrar de qué está hecho.
-> The last match must make the team show whether they deserve to win or not.
- ¿Quieres el aumento de sueldo? Pues ahora es el momento de que muestres de qué estás hecho.
-> The employee must prove they deserve the pay rise.

In sports, they also say "sacar la casta", which means to make an effort to show your actual capabilities.
- Parecía que el corredor iba a quedar en segundo lugar, pero al final sacó la casta y ganó la carrera.
-> It looked like the runner was going to end second place, but he made an effort and won the race.
- El equipo sacó la casta y logró empatar el marcador.
-> The team that was about to lose did their best and finished equal.

"Crecerse", might be another way to say something similar. This means you become better when you have to face an adversity.
- El equipo mexicano se creció ante el fuerte rival y ofreció un buen partido.
-> A weak team was expected to lose shamefully, but they rose to the occasion and they fought back.
- Juan se creció ante las críticas a su trabajo y desde hace dos meses es el mejor empleado.
-> Juan was a mediocre employee and when they told him so, he showed that he could do much better.

I can't think of any other ways to say this. Maybe someone else will find something more appropriate.