Answer:
The following punnet square would be constructed from the above mentioned cross:
b b
B Bb Bb
B Bb Bb
A punnet square can be described as a diagram which is made to illustrate the outcomes of a cross.
The results from the above punnet square show that the offsprings produced from a cross between homozygous blue and brown parent, will all have blue feathers but they all will be heterozygous for the trait.