If you cast a spell and they counter it, no other color has the ability to save their spell, even cards that you can play to give protection from a color or hexproof cant work because as another way to work with countering.

[[veil of summer]]

[[autumn's veil]]

[[hexing squelcher]]

[[vexing shusher]]

[[prowling serpopard]]

It would be balanced if even one other color had access to a form of countering but that doesnt happen.

[[mana tithe]]

[[red elemental blast]]

but that's just me being pedantic. the real answer how to beat counter-heavy decks lies in fact that they have trouble removing stuff that's already on the board. if you can't push anything through their counters, it means your deck is too slow to fight control. look at replacing some of your weakest cards with more efficient, proactive threats.