Thanks for the good review! But I did not get your bonus??
Now, coming back to your question: You did not mention the color of the grand father's eyes as blue.
I think you are slightly confused. Lets get to the basic point.The color of the eyes is "polygenic", determined the color of the eye pigment inside the iris and the frequency-dependence of the scattering of light by the turbid
medium in the stroma of the iris. And as I said, the color of the eyes (like any other gene) has 50% chances for being carried from either parent, depending on whether it is the dominant or recessive gene.
So, if you want the son's eye color hazel with the grandfather having blue eyes, then the grand mother's eye color has to be hazel.
Secondly, if the grand son's eye color is hazel and his father is hazel too than his mother's eye color is either hazel or some other color.
And as you see that both the son and the grand son's eye color is hazel, it is likely the dominant gene.
I hope you understand my explanation.
It was a pleasure assisting you.