My favorite Magic: The Gathering deck is named "Draconic Artifice," a red-black-artifact deck based around cheap modular artifact creatures and cheap direct red damage stringing me along until I hit seven mana, at which point I start droping a certain variety of 5/5 flier. That motif has been increased with interesting trades, and the deck has enough actual dragons in it for Kilnmouth Dragon's amplify to have real meaning. (Kilnmouth Dragon gets +3/+3 for every other dragon you have in your hand when you cast it; I can regularly get him out as 8/8 and almost got him as an 11/11, but triton668
countered that one for some strange reason.)
Anyway, I've remixed the deck; I've taken out almost all the black for more red direct damage. I still have two black cards in the deck, and I am unwilling to remove either: Mephitic Ooze (0/5, +1/+0 for each artifact you control (I usually make him 5/something), if this blocks or is blocked by a creature, destroy that creature at end of combat), and Bladewing The Risen. The former costs 4B, and the latter is 2RRBB. I also use Skeleton Shard, which is activatable for 3 or B. So for you Magic: The Gathering players out there: how much black mana do I need in my deck? I had previously been playing with eight (not counting Talisman of Indulgence), but I just took out two Swamps for a pair of Mountains, so it's currently at six. For a deck that lightly "splashed" with an auxillary, color, is that reasonable?
Note that the mana deviation in the deck isn't generally a problem. I do have a lot of specific red mana, but I also have a whole lot of artifacts who really don't care...