How can a green eyed parent and a brown eye parent have blue eyed children?

I can not insure the accuracy of this but using the punnett Square calculator on this website: www.changbiOScience.com/genetics/punnett.html

theoretically a child with a green eyed parent and a brown eyed parent (not hazel) you would have a 50% chance of having a child with grey eyes (which look blueish) and a 50% chance of having a child with hazel eyes.

These are the genotypes for eye colours that you can use to have a go your self:

EEEEEEEE Black Eyes

EEEEEEEe Brown Eyes

EEEEEEee Hazel Eyes

EEEEEeee Grey Eyes

EEEEeeee Amber Eyes

EEEeeeee Blue-Green

EEeeeeee Green