The advertisement I found is for a masked ball, and created by Jules Cheret. Along with other posters and advertisements from this era, there are several colors and movements happenings. Even though the colors help catch the viewers' eyes, it could be toned down a bit. The capitalized fonts also show that this advertisement is during the Industrial Revolution. I like how Cheret made the people look energetic, which is how one should feel when going to a ball.
As a designer, I would want to focus on tuning everything down a notch or two. The lettering doesn't have to be so big and bold, and there isn't always a need for a large color palette. Cheret has been called "the father of the modern poster," and I think he could vary his style as compared to others to make himself stand out even more.
sources: Britannica Encyclopedia Online