A Question on Double Rainbow Energy

[MisterBlue92]

Hi all, hypothetically, say I had a Pokemon with an attack that stated I have to discard all steel energy and I nothing but rainbow energy attacked.

As I would have no basic steel energy attached (and it doesn't state I have to discard the energy in order to use the attack), would I have to discard Double Rainbow energy or could I attack without discarding anything?

Heres the card I'm hoping to do this with: https://bulbapedia.bulbagarden.net/wiki/Palkia_&_Dialga_LEGEND_(Triumphant_101), I'm referring to the Time Control attack.

 

[Porynoir]

Well, the rainbow energy is a um... magic energy that basically changes into the energy you want it to. So technically, the rainbow IS a steel energy. So, I don't think you could bypass that, but maybe...

 

[donavannj]

It does count as a Metal Energy because it is all types at once, so you would have to discard it.