Update plantcv/plantcv/pseudocolor.py
Update plantcv/plantcv/pseudocolor.py

Co-Authored-By: HaleySchuhl <9a469fe674a7b7843c12bbcf587d77614927fcba@users.noreply.github.com>
stiphyMT/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,danforthcenter/plantcv