Maize kernels

The inheritance of Maize seed (kernel) colour is enormously complex and involves many alleles and mutations.
In 1983, American geneticist Barbara McClintock received the Nobel prize in Physiology/Medicine for her work on the genetics of maize (Zea mays). She demonstrated that the colour genes could jump from one position (loci) to another. She called these ‘jumping genes’ or transposons.
A simple model of Maize kernel colour involves two genes:

C’ Dominant allele that prevents any pigment formation (resulting in white or yellow kernels)
C Recessive allele that allows pigment formation

Bz Dominant allele for purple pigment

bz Recessive allele for brown pigment

Assuming these to be unlinked, work out the possible phenotypes and genotypes of kernel colour in maize when two heterozygous individuals cross.

Calculate the proportion of each of the colours present in the maize cobs. How does this differ from your expected ratios? Can you explain this?