When starting seeds you will notice both types from the same batch of seeds, all seed not only Douglah. I usually start 2 seed per hole and have to decide if I want the green stems or the purple stems to grow. The one I keep is not always the same for each variety, but I find myself choosing the green stems ones more when I have a choice. I am sure both will eventually grow the same plants, the green stems seem fatter to me. Not albino just the a purple stem variety, grow both and see if you find any difference.