Try that, although it doesn't have an exit signal.
I've done a test using notifications, which should work. I'm not entirely sure if this is the same as using the mouseentered() and mouseexited(), if it is, it probably will have the same problem you're experiencing:
color = Color.green
color = Color.red
I haven't tested it on mobile because I haven't set it up yet. But if it doesn't work, it might be a bug.
If you don't mind sharing your project I'd be willing to check it out, maybe there's something being overlooked.