That's true in some parts but to actually understand what you have in mind might render it "wrong" too 
I guess (from your other thread) that you actually want to do the dimming via a Photon, so you won't need nor want a LED Dimmer since you want the easiest way possible to tell the Photon what dimming level it should produce and you don't need the dimmer to do the dimming - or do you?
But if you want the Photon to do it, there are again (at least) two options.
Do you want the wall control have an absolute or relative effect.
If relative, you can use a rotary encoder which only produces a digital signals that can be counted and turned into a change in brightness/color.
If absolute, you may want a potentiometer that (eventually) provides a 0~3.3V signal to the Photon or a rotary encoder with a absolute positon output.