Green feces may indicate that they have eaten rat poison, as the manufacturers include a dye. Most rat poisons are slow acting, so the green feces may be the only sign that the dog has eaten poison...
The worm you will see in feces are usually round worms. Occassionally you will see pin worms that not that easily. Round worms are long i.e. 2 to 3 inches or more, white almost flat looking worms....