Is the fluid that comes down at the end of menstruation, and its color is like clear honey, considered yellowish discharge (ṣufrah)? And is dark brown or black fluid considered turbidity (kudrah) or blood?

Black or red discharge is considered menses. As for yellowish or brownish discharge, it is considered menses if it is connected to blood or occurs during the usual period. Purity (from menses) is determined by dryness or by the white discharge.