(Doesn't count as a Basic Energy card.) Colorless Energy can't be used to pay colored Energy costs
If you controlled the token, Warehouse Tabby's ability will trigger
On the other hand, for small kitchen-table playgroups where the participants know each other and can agree on variations beforehand, relaxing and tweaking (or, alternately, locking down) the Commander rule can lead to some interesting variations, almost like alternate histories
You can even find a surge foil version of a showcase Ring treatment card, borderless rare or mythic rare land, or new Scene Box borderless scene card
Just remember that whichever mode you choose to cast becomes the mana value of the card on the stack and on the battlefield, unlike other, similar built-in cost reduction mechanics like Suspend or Miracle, s o a commander like Yuriko, the Tigers Shadow very much likes Prototype cards, while Vial Smasher the Fierce does not