This is a movie I think I saw at a very young age. I recall a boy being with a hopeless wizard/magician and in one scene, the wizard/magician is at the top of the stairs with a much more powerful witch who then makes the wizard flat and he slides down the stairs.
Whilst the wizard is recovering, the witch then walks with the boy, I think trying to dissuade him from keeping company with the wizard. The wizard/magician was dressed as a magician in a black tuxedo and the witch sort of like Padme in Star Wars Episode 1 - The Phantom Menace with the red outfit on.
I think it was from the 1990s, or perhaps 80s from what I remember, but it was definitely in color.