Trample
Chroma — Primalcrux's power and toughness are each equal to the number of green mana symbols in the mana costs of permanents you control.
Chroma abilities check only mana costs, which are found in a card’s upper right corner. They don’t count mana symbols that appear in a card’s text box.
Chroma abilities count hybrid mana symbols of the appropriate color. For example, a card with mana cost {3}{U/R}{U/R} has two red mana symbols in its mana cost.
This will count the number of symbols in its mana cost while it’s on the battlefield. The ability functions while it’s in other zones, but since it isn’t a permanent while in those zones it won’t count itself.