@allent2000, in European Portuguese, these are two very different words, even though they are linked to the same concept. Pinta is not a noun in this context, but a conjugation of the verb pintar (to paint). Tinta is the actual noun that means paint (noun) or ink.
The possible contexts are also pretty broad for both. You can use the verb pintar for anything that needs to be painted - so, it’s valid for makeup, for construction, coloring books, canvases, etc. Tinta can also refer to many things, from wall paint to pen ink, printer ink, etc. With makeup, just like in English, it’s unusual to talk about tintas; we prefer using the specific names of each product and then describe their colors. The only exception I can think of are liquid eyeliners.
Here are some examples:
- Os atores pintaram os olhos com sombra escura. (The actors “painted their eyes” with dark eyeshadow)
- Ela pinta quadros muito complexos. (She paints very complex paintings)
- Eles vão pintar o quarto com tinta vermelha. (They’re going to paint the bedroom with red paint)
- A impressora ficou sem tinta! (The printer has run out of ink!)