There are 4 different skin color tones.
All the Senegal I.1 draftees were generated with tone 4, the lighter one. Same in Ghana and Nigeria.
It's possible to define a particular set up. China CSBL draftees were all generated with tone 3, a little bit darker.
I don't know if it's a bug or intended, it looks like a default set up is used. Or maybe there is another issue we are not aware of since it's been around for so long. But it is quite odd...