While working on our upcoming title based on libgdx we have found a flaw in the fade actions FadeIn and FadeOut. Both of these actions initialize the alpha of the actor to animate to with either 0 (FadeIn) or 1 (FadeOut). We have now changed the fade actions so that the fade starts at the current value of the target actor.
What that means for you is that you need to make sure that your actors do have the desired alpha value when you start a fade animation. This is especially important when you use a fade action within a Parallel or Sequence action. In most cases you should be fine though. Btw… the FadeTo is not affected
— Moritz (+1 Labs)