Genus vs. Specie

[cali]

Thats because your brother has a brown eye gene (Dominant) and either a blue or green gene (Both recessive) OR brown and a damaged (Any color)
Your brother's wife has a brown eye gene (Dominant) and either a blue or green gene (Both recessive) OR Brown and a damaged (Any color)

Both children have one of the following- either Blue x Blue, OR Blue x Green (Blue is dominant over green) OR Blue x damaged brown (where the recessive gene takes precedence over a normally dominant damaged gene)

NEITHER OF THOSE CHILDREN CAN PRODUCE A BROWN EYED CHILD. PERIOD.

[cali]

Just as 2 albinos can NEVER produce a normal phase. They only carry recessive genes.