Probably because they animated in color in the first place. The color POTD was a waste of time.
Charles Norton’s team only produced a b&w Power, but they’re doing Shada in color now.
The color Power was made by a Canadian team unrelated (and unendorsed the way Charles describes it) by the actual team. That came about when BBCA got involved and wanted to broadcast it.
Hopefully Shada is great. Glad the aspect ratio is correct, and hoping the location filming is all HD and nicely restored.