Crosses between a yellow rat with a yellow rat always produce yellow. Crosses between a white rat ...

Crosses between a yellow rat with a yellow rat always produce yellow. Crosses between a white rat
  with a white rat always produce white. The alleles affect the same aspect of coat color. The crosses of
  a white with a yellow produce a cream. What happens if you cross two creams? What will be an ideal response?
 
 

Question 2

In horses, black coat color is influenced by the dominant allele (B), and chestnut coat color by the
  recessive allele (b). Trotting gait is due to a dominant gene (T), pacing gait to the recessive allele (t).
  What color horse would you use to find out the genotype of a black trotter? Give the genotype and
  phenotype. What will be an ideal response?