I would like to mention 2 things about the trophies from the difficulty levels.
First of all - each trophy, with the exception of the iron one (the easiest mission), has a number of stars that show the difficulty level. The trophy (hard mission) has 3 stars and the rest from the top have the same number of stars than, for example, 5 for an elite mission.
Secondly - these 3 hard mission trophies are the same color and nothing special is not that different, only the changed texture in very hard mission and the addition of a bow and beads in the elite trophy.
I would like to show you what I think these two trophies could look like
Very hard Campaign trophy (diamond)
Elite Campaign trophy (crimson (or maybe ruby?))