I am getting ready to submit my CSS profile and am wondering if it affects my admissions in any way or only considered after admission is decided? Do colleges prefer students that can pay full tuition or do they look for students with a financial disadvantage?
It all depends on the school.
If the place is need-sensitive for admissions, how much they like you will determine if you get the aid they think that you need (and consequently if you are admitted).
But if they don’t like you enough to give you the aid that they think you need, then clearly you don’t want them either. 
@Isabellight
Hi: The term is known as ‘need-blind admissions’. At one time, just about every institution in America claimed that their admissions selection process was need-blind. In recent years, however, that has changed.
To clarify, whether adcoms even know you’re applying for aid depends on school policies. You can see that in their web info. If they’re need blind, they don’t know. If need aware, there are different ways this factors. Some only use your “need” when one is ok for an admit, but borderline. Others use it when they’ve built most of the class and projected remaing funds are limited. Etc.
Other schools are “need-blind” but only for domestic applicants, and need-aware for international applicants.
Like said earlier, it all depends on the school