Multistand
For my Three-colour Reprappro Mendel I made this Multistand, just click them on your Mendel, hang a rod in, and use any spoolholder to hang your spindels in.
The Reprapworld spools are too wide to hang 3 in one row, so, I hung one on the other side.
But spools that are not so wide you can hang all on the same side.
Changing spools is easy, just tke the rod off and change.