I suppose there is no objections to have the aircraft painted as long as it doesn't come from their own pocket.
Passengers will likely not know any difference until the PA announcement on board where it will likely be.
"Good morning and welcome to your EZYxxx flight to XYZ operated by xxxxx"
I have to say allthough the reason for these wet leased aircraft are suspicious be it short of crew or late delivery of aircraft. At least they are trying to minimise the impact by bringing in other airlines to operate flights on their behalf.