A dispute came up in a game. I let the players know that the Dryad Arbor was now a Green Mountain Creature and could be sacrificed to Dystopia but some were under the impression that changing Dryad Arbor to a Mountain would make it Red. I would request final confirmation on which scenario is 100 percent correct. Thanks!
Blood Moon does nothing to change the color of permanents; therefore, Dryad Arbor becomes a Mountain but stays green and can be sacrificed to Dystopia.
Blood Moon won't change it to red. Turning lands into mountains doesn't necessarily means they become red because normally, all lands are colorless unless otherwise specified. Blood Moon doesn't have the ability to change colors. Dryad Arbor remains green (and a creature) with "T: Add R to your mana pool."
One of the official rulings on it is:
"9/22/2011 If Dryad Arbor is changed into another basic land type (such as by Sea's Claim), it continues to be a creature and a Dryad."
Dryad Arbor
Dystopia
A dispute came up in a game. I let the players know that the Dryad Arbor was now a Green Mountain Creature and could be sacrificed to Dystopia but some were under the impression that changing Dryad Arbor to a Mountain would make it Red. I would request final confirmation on which scenario is 100 percent correct. Thanks!
One of the official rulings on it is:
"9/22/2011 If Dryad Arbor is changed into another basic land type (such as by Sea's Claim), it continues to be a creature and a Dryad."
There is also a forum similar to this: here