UIFont does not contain/maintain any color information, so this is not possible. In general, controls that use UIFont such as a UILabel have both a font and a textColor property. So you would set a label's font and it's color like this:
myLabel.textColor = [UIColor blackColor];
myLabel.font = [UIFont fontWithName:@"Helvetica-Bold" size:8.0];
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…