Luckily, advances in effects that have taken place in recent years meant that Gillan didn’t have to go to the extreme that she did for the first Guardians movie of actually shaving her head to play the bald-headed Nebula.
That would have made doing any other work over the last couple years quite difficult as she would have needed wigs to make any other film in between Marvel projects.
Karen Gillan has spent an awful lot of time blue recently as prior to beginning her work on the Avengers movies she had to film Guardians of the Galaxy Vol. 2, so she’s actually made three films in fairly short order that required the extensive makeup work.