Presuming you don't have many other routes to fix your mana, then I'd definitely wait until you can deploy your partially off-color six-drop
Among them is Sami, a 2/4 Human Artificer for four mana, representing the story's human element
(To mill two cards, a player puts the top two cards of their library into their graveyard.) The card you put on top of your library, if any, may be one you just milled, or it can be one that was already in your graveyard
Treasure has only become more powerful since its initial printing too, so if you manage to get one of these in Double Masters, hold onto it
How do I redeem MTG Arena Codes on PC/Mac
There were initially discussions of only cards which could plausibly be on Ikoria, and we threw that out the window pretty quickly: it was far too limiting