Esoterica: Entropy Reflector

Whenever a legendary permanent enters the battlefield under your control, for each color in that card's color identity, add one mana of that color to your mana pool, then
if it has colorless mana in its mana cost, add {c} to your mana pool, then you may draw a card. (For example, if a permanent with mana cost {2}{r}{w} enters the battlefield under your control, add {r}{w}{c} to your mana pool.)