P is allele for red 
Q is allele for white 
PP is homozygous genotype for red and its frequency is p 2
QQ is homozygous genotype for white and its frequency is q2 
PQ is hetrozygous genotype for roan with the frequency 2pq. 
If the poppulation is in HW equlibrium than p2+2pq+q2=p+q=1 
p= 476/467+323+51=0.56 p2=0.3136 
q=51/467+323+51=0.06 q2=0.0036 
pq=323/467+323+51=0.38 2pq=0.0672 
0.56+0.06+0.38=1 
The population is in Hardy-Weinberg equilibrium.