Answer :
Using r for red crayons, g for green crayons, and c for any color crayon:
r + g = 16, r = g = c
c + c = 16
2c = 16
c=8
r =8, g = 8
r + g = 16, r = g = c
c + c = 16
2c = 16
c=8
r =8, g = 8