chromatic combustion

you gain two life for each {w} spent to
cast this spell
you draw a card for each {u} spent to
cast this spell
each opponent loses 1 life for each {b} spent to
cast this spell
chromatic combustion deals 1 damage to any
target for each {r} spent to cast this spell
put up to one +1+1 on target creature for each
{g} spent to cast this spell