Most colleges are need blind for admission when evaluating individual applicants in a strict sense regarding the financial aid application.
But since almost every aspect of an applicant’s application characteristics has correlation to SES, it can be rather hard to be truly SES blind if there is any selection at all (as opposed to open admission).
But also, colleges are typically need aware for the entire class when doing budgetary planning. This may cause a college to adjust the weighting of various SES correlated admission characteristics to meet a target financial aid level for the entire class, while maintaining a need blind policy for individual applicants.