When I try setting the color of a UILabel to the color of another UILabel using the code
myLabel.textColor = otherLabel.textColor
myLabel.textColor = UIColor.redColor()
The easiest workaround is create dummy labels in IB, give them the text the color you like and set to hidden. You can then reference this color in your code to set your label to the desired color.
yourLabel.textColor = hiddenLabel.textColor
The only way I could change the text color programmatically was by using the standard colors,