Information about the effect provided by the upgrade for the armor can be seen above the list of resources needed for crafting it (check the picture below). No pieces of power armor equiped to modify :: Beware of disappearing power armor in Fallout 4 Power Armour - Multiple Mods - Fallout 4 Mod Angelis.
Powered by a back-mounted TX-28 micro-fusion pack generating 60,000 Watts of energy, the HiFlo hydraulics inside the frame increase the operators strength and carrying capacity. The West Tek internalized servo system is the standard chassis for all power armor series.
In addition to that, each type of special modifications varies depending on what part are you upgrading (leg modifications aren't similar to helmet modifications). The power armor frame is the basic exoskeleton unit required for all power armor models in Fallout 4. Special modifications can for example increase the springing speed, increase the capacity, provide invisibility while crouching or allow flying thanks to jetpack. Special modifications are various upgrades that impact the functionality of the Power Armor and character statistics. Details can be found in the Magazines chapter. There are three magazine types - each of them will unlock one unique paint schemes: Shark, Hot Pink and Flames. You can obtain them from the Hot Rodder magazine.
Paints are special type of material modifications. To gain access to all material modifications, develop Science! (rank.