I almost sorta think I kinda understand what he means with the grass energy thing....
Lugia:
If a pokemon has a colorless attack cost, like, for example, base set rattata's bite attack:
:colorless Bite 20
And you attach a :grass: energy to it, you have satisfied the requirement for its attack, and may use it. However, just because the attack's requirement is a colorless energy (or, if you prefer, an energy of any color- "colorless" is actually sort of a misnomer, because it is the presence of any color that satisfies the condition, rather than the absence of all color), does not change the :grass: energy attached to rattata to a :colorless energy. The grass stays grass , without regards to whether it is attached to rattata to be used for a colorless attack or not. Thus, if it was put back into your hand, it would still be grass . On rattata, it is still :grass: . There are a few pokemon powers that can change that (a porygon, a lanturn), but the card itself stays a grass energy. This becomes important in game play, because there are a number of pokemon that do damage based upon the number of a certain type of energy in play: Hidden Legends Gorebyss does ten more damage for each
sychic: energy in play, regardless of what type of attack the
sychic: energy in play is meant to be powering.
Hope that helps, and hope I understood your question,
Cheers,