the cell masters are the older chargers they have, they doa fantastic job of charging NI-MH packs with soo many features. The cell masters come in, black, blue and purple. Its also a DC only charger meaning you need a p/s.
Their newer line of chargers are the silent chargers, they can do Li-po and NI-MH, the silent chargers only come in black.
The silent chargers still do a fantastic job of charging NI-Mh so don't be afraid to get one of these over the cell master. They come with and without power supplies built into these. The ac/dc has the supply in it from the factory so it costs more, but if you already have a p/s then get the DC version.
If your concerned about the color and really want the silent charger because it does li-po, buy the silent charger, and then the cell master in your chosen color, swap the board from the silent charger into the colored case of the cell master and the fans. Then you will have a colored silent charger! If you need a write up on this I can step you thru it, its very simple.