It may surprise you, but either is correct. Whose is an interesting word and very flexible. It is a possessive form of the pronoun Who + is to show possession or association with something. For example "Whose cereal is this?" Someone owns this cereal but we don't know who. It usually appears before a noun. So "Whose car is this?" and "Whose red car is this?" are both fine. Just be sure not to confuse it with "Who's" which is Who + is as in "Who's going to the party on Friday?" This form can easily be broken into Who + is, and is shortened for ease only. Whose isn't broken down to "Who + is." Hope this helps a little. If you need more help, feel free to message!