Incomplete dominance is just a fancy way of saying that the more "dominant" or pronounced gene doesn't get to express itself completely when it's heterozygous, or paired with a lesser (not the same) allele. Note that anything "homozygous" just means that the paired alleles are the same ones.
So, red is dominant & white is recessive. When bred together, all the offspring will be mixed breeds or "heterozygous". Keep in mind that red does not completely take the spotlight.
Red+white (incomplete dominance means that they have to share the spotlight)= pink babies.
