One possibility is morally ambiguous:
Donald Trump may have done some good things as president, but he has
said some nasty things as well, making him a very morally ambiguous
person.
from Merriam-Webster:
moral ambiguity (noun) : a lack of certainty about whether something is
right or wrong
Characters in literature and films (e.g antiheroes, sympathetic villains, lovable rogues, rakes etc.) are often referred to as “morally ambiguous” if they exhibit both a mix of good and evil in their actions and/or motivations.
Alternatively you could use amoral:
from Wikipedia:
Amorality is an absence of, indifference towards, disregard for, or
incapacity for morality.
However this implies an absence of morality rather than a mix of both good and bad - which could be more apt description depending on the case - but since you asked for a mix of both good and bad, I will defer to my initial answer.