If I have four Plasma Energy in play, either on the field and/or in the Discard Pile, can I use Colress Machine to search through my deck, find nothing, and shuffle my deck?
No you cannot. Since the location of all four Plasma Energy cards are known, there's no way Colress Machine would be able to find one during a deck search.
Source: TPCi Rules Team (2013-02-28); TPCi Rules Team (2021-07-01)

Relevant cards

Note: All applicable cards may not be listed below.
BW8_119
BW8_127