Whenever one reads literature, it is always important to understand the culture in which the work is set as well as the culture of the author. Perhaps, with no other of his plays more than The Merchant of Venice is this so necessary. In fact, it seems rather odd that the Prince of Morocco would even present himself as a suitor since the Ventians were a very closed society, perceiving themselves even superior to other Italians.
So, when the prince from the African country of Morocco presents himself as a suitor, he initiates the conversation by asking Portia to not judge him by his superficial appearance, saying his blood is as red as any white man's underneath his dark skin. At this point, Portia does not like any of her suitors; so, she responds,
In terms of choice I am not solely led
By nice direction of a maiden's eyes:
Besides, the lottery of my destiny
Bars me the right of voluntary choosing: (2.2.13-16)
Thus, Portia indicates no racial prejudice since she cares not for any of the suitors; besides, she has no choice, anyway, since her father has arranged her marriage by the choice of the caskets. Nevertheless, in Scene 7, after the prince departs Portia says,
A gentle riddance. Draw the curtains, go.
Let all of his complexion choose me so. (2.7.78-79)
This remark certainly indicates her feelings, feelings which would be in keeping with the attitudes of the Venetians and Elizabethans alike.