At the end of my menstruation, I don’t get completely white discharge or dryness, but light yellowish discharge, which I also have normally. I even wait to make sure there is no significant yellow, brown, or red discharge. Can I count this as the white discharge and hence the end of my period?

Yes, you can count it. The white discharge is the usual sign of purity and not a required one, and Shaykh Ibn Uthaymin said that for a woman who does not see it, the yellowish fluid that is her normal state stands in its place, so once the blood of the period has ended in your habit you are pure, you make ghusl and you pray.