Matplotlib issued the message:

UserWarning: You passed a edgecolor/edgecolors
XXXX for an unfilled marker.  Matplotlib is
ignoring the edgecolor in favor of the
facecolor.

My marker is “+”. To me, it has no area, so I would expect “edge” to be relevant rather than “face”.

Is this just a matter of “tomawto” vs. “tomayto”? That is, does the message mean that it using my edge color specification?

It’s hard for me to tell because I have a sequence of RGB values, one for each point, sampled from seaborn‘s deep colour palette. Some of the points have the same RGB colour, depending on various other factors.