Trying to animate the color alpha of a UI button does not work on windows phone if the alpha values were set to 0 in the button settings.

To reproduce:
1. Open repro.unitypackage
2. Open test3
3. Enter play mode in the editor - notice the fading button image
4. Build & run to a windows phone
5. Notice that only the text is visible but the button image does not appear at any point

The animation works correctly if the color alpha values on the button are set to 1