To change the color of any object or text you want to use UIColor. With UIColor also possible to set the transparency.
UIColor objects can be created in a variety of ways:
-UIKit Provides standard system colors that you can use to match the colors of your own UI objects to those provided by UIKit. You can use these colors without needing to understand the underlying representation of color. See Creating System Colors.
-UIKit Provides definitions for very basic colors, such as red, orange, yellow, and so on. See Creating a UIColor Object with a Predefined Color.
-You Can create a custom color in a Core Graphics color space. See Creating a Custom UIColor Object in a Specific Color Space.
-You Can create a color object from another object, such as another UIColor object, a Core Graphics representation of a color, or a Core Image color. See Creating a UIColor Object from another Representation of Color.
-You Can create a color from a UIImage object, which is used to paint a repeating pattern instead of a solid color. See Creating a UIColor Object that Draws Using a Pattern.