https://magic.wizards.com/en/articles/archive/magic-digital/tinkerers-cube-comes-mtg-arena

White/Blue: flying creatures and blinking
Blue/Black: discard-and-reanimate and on-hit effects (dealing combat damage to the opponent)
Black/Red: treasure and sacrificing creatures
Red/Green: large creatures and fighting
Green/White: tokens and enchantments
White/Black: lifegain and +1/+1 counters
Black/Green: deathtouch and self-mill
Green/Blue: lands and artifact tokens
Blue/Red: looting and spells
Red/White: equipment and graveyard matters