How does 'gris' change depending on gender and number?
So I've learnt that colours change depending on the gender of the noun they are describing (with the exception of 'azul' and 'verde') and also the number of nouns they are describing.
What's the case with gray? It didn't show it in the table. At a guess I would say it follows a similar pattern to 'azul' and 'verde', in that it would be 'gris' regardless of gender, and maybe 'grises' for plural.
Adjectives that end in anything other than "-o" or "-a" have singular and plural forms, but not gendered forms.
La taza gris, el auto gris :-).
Only grisáceo/a, azulado/a, verdoso/a changes.
My tip is: everything follows singular/plural pattern (well, I think it does, doesn't it?), just not everything follows masculine/feminine pattern. There are words (like you mentioned) that have only one form, not depending on the gender.