The gene for fur color in rabbits is an incompletely dominant situation: BB rabbits are brown, Bb rabbits are grey, and bb rabbits are white. The gene for fur color distribution is however co-dominant. This gene, S, has two alleles, S1 and S2; S1S1 animals have stripes only; S2S2 animals have spots only; and S1S2 animals have both stripes and spots. The S gene cannot be expressed in white rabbits.

Question

The gene for fur color in rabbits is an incompletely dominant situation: BB rabbits are brown, Bb rabbits are grey, and bb rabbits are white. The gene for fur color distribution is however co-dominant. This gene, S, has two alleles, S1 and S2; S1S1 animals have stripes only; S2S2 animals have spots only; and S1S2 animals have both stripes and spots. The S gene cannot be expressed in white rabbits. 
a) If one grey (striped and spotted) rabbit with a white rabbit (that is a carrier for spots only are bred), what are the genotypes and phenotypes expected?
b) If one the grey, striped and spotted parent is crossed with a brown spotted rabbit, predict the offsprings' genotypes and phenotypes.