The bigger, colorless colors (BG, BU, UG)

I'm lumping these three together because these are the colors that will speak to you when you land a sweet colorless rare. Perhaps one of these

 

But also note that the larger colored-colorless also tend to be in these colors. Namely:

  

So on and so forth. These are the decks that will prioritize Wastes, colorless mana symbols, and grinding out the win with some sort of longer term win condition (often a dumb big creature, card advantage, or something similar)

Manafixing (colorless-fixing)

    

Colorless Payoff

     

Traditional Ramp Payoff

 

Increased Value in BFZ