Instruments, Xcode’s tool to track and analyze your application’s process, has a cool little feature that lets you turn your iPhone’s screen into a sea of red and green that came straight out of Microsoft Paint. To turn this little feature on, open up instruments and create a Core Animation instrument for the iPhone. Click on the detail view icon in the bottom left of the window, and a bunch of debug options will pop up. Check the Color Blended Layers box. Now you have a good April fools prank, but this view is actual helpful when it comes to optimizing your iPhone animation performance.
The key to this color blended layers is simple – green is opaque (good), red is transparent (bad). If your application has a table view, and you are scratching your head wondering why the table doesn’t scroll like butter, look no further than this filter (okay, make sure you reuse cells too). If you can turn your views from transparent to opaque (turning red to green) you’ll notice your table start to scroll a lot smoother. Tuning your application to animate with ease is an acquired skill. You really have to play around and see what will run smoothly. Of course, there are pros and cons to many decisions you’ll make. In terms of animation performance, the more you eliminate transparency, the greater the performance.
label.backgroundColor = [UIColor clear]; // this is not your friend