User blog comment:AnimePerson1/Storage.....????/@comment-26828130-20180308204817

You know about the items with green amount numbers? They are either bought with gems, or rewards required for contracts/achievements They can be left in storage, as they don't take storage space

Items with the amounts in black take storage space, if you want to keep them, store them in depot behind your biggest unused loco's

Also, shop items can always be bought, sell them if you don't use them