For the purpose of college auditions, I think you need to choose material from characters you can realistically play. This is not to pigeon hole anyone into a type for their career. But it does show the auditors you have a general understanding of what material is suitable for your age, size, ethnicity, etc. They need to see who you are and how you portray a character onstage. You don’t want them to be distracted by presenting material that makes no sense (ie playing someone too old or too unbelievable). I think sometimes there is also a mistaken idea that the more you stretch, the more impressive it will be to the auditors. This is not so. They want to see you truly embrace a character and portray them well. They want you to be believable as the character you are presenting. Make them feel what your character is feeling, believe what they are saying, embody the character to its fullest. That’s what they want see from you.