On what condition is the speaker prepared to change his dark complexion?

The Prince of Morocco refers to his complexion when wooing Portia. He is aware of the racism against men with his skin color. Earlier, Portia expressed frustration at having to face yet another suitor: “if he have the condition of a saint and the complexion of a devil, I had rather he should shrive me than wive me.” By “complexion of a devil” she is referring to the prince and his dark skin.
The prince immediately addresses these concerns, referring to his skin as “The shadow'd livery of the burnish'd sun.” He has no problem with his race, knowing that he is as brave and worthy as any. He even brags that beautiful women in his country have loved him for his looks, including his tawny skin. However, the only reason he would change his skin color would be to win Portia’s approval: “I would not change this hue, / Except to steal your thoughts, my gentle queen.”
Portia assures the prince that he has as good a chance as any suitor, since she is unable to select her husband herself. He fails the test that her deceased father set up and must leave in shame. Portia seems to have some respect for him, but she says, “Draw the curtains, go. / Let all of his complexion choose me so,” expressing a disdain for men who are not white.
http://shakespeare.mit.edu/merchant/full.html