Before revision:  (3) There are arbitrarily large point sets R\cup B in general position, with |R| = |B| +1, such that at most r+b-5 points can be K_{1,3}-covered.
After revision:  (3) There are arbitrarily large point sets R\cup B in general position, with |R| = b +1, such that at most r+b-5 points can be K_{1,3}-covered.