I wanted to draw with blending effect. The color changes eventually from color A to color B. Therefore I have to set the pen color frequently. But I found that no books or MS Visual C++ help file talks about changing the data of a pen. They just told me how to create a pen. If I create a pen and destroy it and then create another one, the on draw function will surely become very slow. How can I change the color of a pen after it is created?