I have a ceiling fan+light that is already installed on the ceiling, and I
want to install a controller that has a light dimmer and a fan speed
controller in one assembly. I have said controller in hand.
The switch has two black wires, a blue, and a green.
The switch box in the wall has black/white/ground coming from the breaker
box, and black/white/red/ground going to the ceiling. I know for a fact that
the fan assembly is installed correctly -- that black/white goes to the
light and red/white serves the fan.

1. How are two blacks, a blue, and a ground wire supposed to be hooked up in
the switch box?
2. If the fan is a three-speed fan, that means I cannot hook up a slide
controller at all, right?

Thanks.