See Shimmering Sands and Forgotten Glade. This is a fusion of those two concepts.

It’s a little pushed, but not unreasonable. Is there a reason you’re calling out , specifically?

Ok; so either "Whatever colour you need, and also put a card from your graveyard on the bottom of your library" or it can just be an ETBT plains.

The upside is rather good - not tapped, gets a card back, and is whatever colour you needed. But it is quite hard to trigger early on. Dunno; I guess how good it is depends on how important it is to return cards to library; and how much the set has in the way of 1 and 2-drop sorceries.

Just putting this here so other people don't need to dig around.

"Reminisce: Put a card from your graveyard on the bottom of your library."

I understand that reminisce is important to your set. But I can't help but think that its a shame this isn't employing imprint. Especially since I could easily see this card being used in a three color deck, but the memory issues are going to be super problematic since the card used isn't even in the graveyard to look at anymore.

Generally when I notice that my mechanic would have been more appropriate choice for another (imaginary) set, I double back and make the presumption that there was probably a stronger choice for this set. Maybe when you reminisce, you add one mana of the color of your choice? Presuming the land always enters the battlefield tapped, you're still only getting one mana per turn. The resulting land would give you some flexibility if you could reminisce (vaguely reminiscent of the Tendo Ice Bridge), but just be an etb tapped land if you can't.

@continuum: Every Desert in the set currently produces to support the small selection of cards which include in their cost. Every non-basic land in the set is a Desert.

@jmgariepy: I guess I can't see why imprint would be better. Reminisce is a cost for the upside here, but the chosen color isn't based on the card you reminisced about. There's no reason to need to reference that card later. Is that somehow more confusing? Do you think this has more memory issues than Heraldic Banner or Coldsteel Heart? If so, I can try to come up with an alternative.

A cycle of Forgotten Glade is a possible, simpler alternative, though it doesn't solve my desire to seed in potential blue sources.

I was originally imagining a theoretical card that used the mana type from the card you reminisced. Somewhere, when editing, I switched over to 'of any color' since that seemed too weak. But I missed my previous comment about imprint, which was now confusing. Sorry bout that.

As for Heraldic Banner / Coldsteel Heart: Yes, I think this has many more memory issues than those two. Because this is a cycle, and the rare land of the set, which means that you could expect to see eight to twelve copies in many decks. Some games would have three on the table by round three without batting an eye. Granted the first land probably wouldn't reminisce anything... but you still have memory issues remembering which of those lands was your first land.

In contrast, Heraldic Banner will probably only sees infrequent use, with no guarantee of being 4x in a deck. Coldsteel Heart is far more ubiquitous, but the maximum number of Hearts in standard at any point was four. [JM from the future. It occurs to me that you could play Coldsteel Heart x4 and x4 Paradise Plume. But that rare combination would probably be in a mono-color deck anyways.] I'd also argue that casting a Heart on round two is a more memorable event than whatever color your land happened to produce when you're more concerned about playing your Silver Knight.

I have zero problems with Forgotten Glade. But I understand that sometimes the simplest method doesn't fit a set's needs.

Ah, so the memory issue is more because of the potential frequency. That makes sense.

I created Nostalgic Pasture and Nostalgic Field as additional options.

Use Forgotten Glade over this any day of the week.

If you for some reason are enamored with this design, make it a single card without the fixed colored mana option rather than a cycle.

I'm not enamored with it, and as a standalone design I greatly prefer Forgotten Glade. That card just doesn't solve what I was trying to solve when I made this one.

Well, that happens if you want to make a world without blue mana.

Does something Unstable Frontier or Ancient Ziggurat satisfy your desire?

Yeah, those are both probably better options.

Similar space to Thriving Bluff.