Propaganda Posters

I have been doing research into these as it fits in nicely with the work I am creating for Visual Problem Solving with people trying to manipulate peoples thoughts etc.
I like the simplistic compositions and imagery within this posters which are far from complex so the message is clear and to the point. I also like the use of a colour palette and this not ranging too much, often with 4 colours being the maximum amount. I am hoping to incorporate similar qualities within my own work, and possibly create one piece very like this.