InterCity trains are only a bit faster than express trains. They have always 1st class with open seating and compartments. See VRs info. Express Trains Express trains have blue livery. Trains have normally self- service restaurant and telephone.
Many trains have video coach too.
There is no express train supplement. On most long distance trains, seat reservation is possibly, but not neccessary unless you are traveling on Friday or Sunday afternoon. On InterCity and Pendolino S220 trains seat reservation is obligatory. Coaches have red livery. On night trains, sleeping-cars are available with one, two or three beds per compartment.