Door to nothingness

[BlackJester]

{Prismatic Omen}

[Kuberr]

{Prismatic Omen}

No. That doesn't Actually let you tap for different color mana.

This one reads "all lands you control have tap add any color mana to your mana pool"

[BlackJester]

{Prismatic Omen}

No. That doesn't Actually let you tap for different color mana.

This one reads "all lands you control have tap add any color mana to your mana pool"

Yes, actually, it DOES let you tap a land for any color.

There's also {Joiner Adept}, which may be the card of which you're thinking.

[Kuberr]

That's the one I was thinking.

[EtherealKris]

I've been messing around with a primarily mono green ramp way of doing a door deck mainly because when I cracked my booster box I got three lol. Once I work out the kinks I'll post it

[JaCe BeLeReN]

An all artifact Myr ramp with door and Emrakul as win cons.

[Kaleo42]

Let me point out that {door to nothingness} enters tapped. You either need to untap it or protect it.

[BlackJester]

Let me point out that {door to nothingness} enters tapped. You either need to untap it or protect it.

{Clock of Omens}, especially if you're going the arti route.

[Kuberr]

{Voltaic Key} seems more practical.

[BlackJester]

I was trying to constrain myself to Standard (for once).

[Kuberr]

{Clock of Omens} is standard? Says Fifth Dawn.

[Hays413]

{Clock of Omens} is standard? Says Fifth Dawn.

And M13

[Kuberr]

Ah. Well whatever works.

[Dywolf]

{Clock of Omens} is standard? Says Fifth Dawn.

Yes in m13

[Quackmaster5]

{Prismatic Omen}

No. That doesn't Actually let you tap for different color mana.

This one reads "all lands you control have tap add any color mana to your mana pool"

Yes, actually, it DOES let you tap a land for any color.

There's also {Joiner Adept}, which may be the card of which you're thinking.

It's basically the same concept as the omen but in creature form.  Doesn't benefit for cards like {last stand} or {keeper of progenitus} though.