Very well endless_sleeper. Got to remember of course: "barva" is feminine, although with TO the adjectives, even being colors, have to be in neuter. At least in standard Czech. Another question. How do you translate in Czech "Is it the orange or the purple one?" Thanks Endles_sleeper for helping us all here on the course!!
You can also say "Je to oranžová nebo fialová?", where both the adjectives are declined according to the feminine noun "barva", hence the feminine endings. It's sometimes clear from the context that you mean colour, so you don't need to explicitly say the noun in the sentence (eg. asking about the colours on the traffic lights).