Not much to say about this card besides the fact that it's a worse Grand Coliseum or City of Brass. The only difference is that this comes into play untapped whereas Grand Coliseum doesn't and this can produce colourless without dealing damage whereas City of Brass can't. But really, is 3 damage worth that 1 coloured mana? I'd prefer giving someone a creature, like with Forbidden Orchard, rather than take 3 damage.
Pros: Can produce any colour of mana infinitely, doesn't come into play tapped Cons: Deals 3 damage for producing coloured mana Rating: 1/5