"노랑이 어디에 있어요?"
Translation:Where is yellow?
I've used it in class, asking it when someone drew a rainbow missing a color.
I think it would be more natural to ask "Where is the yellow?" in that situation. Or (not matching this exercise) "Is a color missing?" or "Isn't there supposed to be yellow somewhere?"
Not in lazy English. It's easier to drop off words and say "where is yellow?"