The OP was kinda short, so I'd like to take a moment to talk about the subtleties that I think make this card so interesting. I'd like to start by saying I don't believe it has a place in type 1, but could very well be playable in type 2 or perhaps legacy/extended (none of which I know anything about at all) and is a cool draft card.
First, the property I vaguely mentioned in the OP, is its drawback. The fact that simply using the card to make mana, by spending mana, actually causes you mana complications is pretty cool. Obviously the card increases the size of spell you can crank out in terms of CMC, but it also neuters your ability to fill out colour requirements in casting costs. Since it makes
you want to use it on spells that have a CMC of 4 to get use out of it as early as possible, but a great many (I believe most?) 4 mana spells have more than 1 coloured mana in the cost. So, if you want to use this card efficiently, cards that cost 2 coloured mana will want to fall to either side of 4CMC when possible. This is also taken into account in the way it curves; you drop this on the first turn, play a spell normally on the second turn, and on the third turn you want to finally squeeze something out of this, but doing so requires a certain sort of spell. If you should manage to get 5 coloured mana producers on the table you suddenly have a great deal of mana available to you, but you also have 5 lands down so you're not causing an early game rukus.
It's costed like a piece of equipment. It's 1 to cast because (as a designer, not a player) you need to have it available to you when you have the mana to spend using it to power out spells, but it costs 2 to activate because it is a significant effect and you don't want people throwing it around left and right. I was sort of considering costing the artifact itself at 0, since it can't even do anything without pumping mana into it. This would take it off the curve entirely so you wouldn't draw it third turn and be forced to either hold it or not play a coloured spell above 2 CMC.
I am not sure how much stronger this card card would be in an artifact based deck. Obviously it would be better and you would be able to start using it twice in one turn considerably sooner, but I think it having a little synergy with other artifacts is actually interesting.
It's the fact it is so elegant with only 1 line of text interacting so deeply with the game that I find intruiging. WotC saw that cheap artifact mana like Moxen caused serious problems in the early game and should be an investment, so they started making mana artifacts very costly to cast. I reversed the logic, and made it awkward to use instead.
Since I'm not sure myself I'd like to hear peoples' impressions about it's power level and the idea of costing it at 1 or 0. Anusien said make it cost 4 (!) but I don't see how that's fair at all, since it only makes 1 mana and is capable of giving you headaches when you use it.
edit: one last thing, infinite mana combos. I knew they were there when I made it (I always wanted to break bog initiate!) but thought nothing of them since 2 card mana only combos are bad in vintage. But since they could potentially have an impact on other formats, I think a line that says "This mana may not be spent to pay for activated abilites that generate mana" is a better solution than making it tap. I can add that now.
In fact, is this better than the coloured requirement?
