Zur the Weird

Whenever you cast a spell, as you cast it, you
may target that spell and replace all instances
of one color word to another or one basic land
type to another. For example, you may change
"nonblack creature" to "nongreen creature" or
"forestwalk" to "islandwalk."
If the targeted spell is a permanent any changes
made will remain for as long as that permanent
remains on the battlefield.