It's about twins that have magic powers and they go to a [purple] mountain and are transported to another world, and I saw it on the disney channel years ago.the twins are adopted and held prisoners in order to keep their powers in control.

it's about twins that have magic powers and they go to a [purple] mountain and are transported to another world, and i saw it on the disney channel years ago.the twins are adopted and held prisoners in order to keep their powers in control.
Escape to witch mountain starred a young jodie foster

It could also be the 1995 remake of "Escape to Witch Mountain" since that's the only one I know of that aired on the Disney Channel.