Napoleon had Spain as an ally until after 1805 when they were defeated at Trafalgar, in the later years of the wars they really only had Polish and German allies, but France was one of the richest most powerful nations of the time.
Polish Lancers (Left) -
So far these are the only allies I have for the French, but am constantly researching uniforms for future projects.
First featured I believe in the book "Sharpe's Gold" they carried vicious looking lances. These men have custom designed torsos printed on sticky labels, and pendants on their lances although these aren't too clear here.
The have blue torsos and legs, and yellow epaulettes. The shakos also have custom hat badges.