Black and white shirts
05AB1E, 14 bytes

*Š*‚[ICÓ-W_iõq


Try it online!

Uses p instead of b, because pink is prettier than black.

Explanation:

*             # number of white shirts * durability of white shirts
 Š            # swap
  *           # number of pink shirts * durability of pink shirts
   ‚          # pair the two products in a list
[             # infinite loop
 I            # get the next input
  =           # print (only in the TIO version, not actually needed)
   C          # convert from binary (this yields 51 for p and 58 for w, don't ask why)
    Ó         # list of exponents in the prime factorization
     -        # subtract from the durability list
      W_i     # if the minimum of the list is now 0
         õq   # exit without printing anything