Does Veil of Summer counter a counterspell targeting your spell if you cast it in response?

When an opponent casts a counterspell targeting your spell, you may cast Veil of Summer in response (before the counterspell resolves). Veil of Summer resolves first, giving your spells hexproof from blue and from black until end of turn.

Hexproof means your spells and permanents cannot be the targets of spells or abilities your opponents control that share the relevant color identity (CR 702.11). Because the counterspell — typically a blue spell — is targeting your spell, that target becomes illegal once hexproof is applied.

When the counterspell then tries to resolve, the game checks its targets. Under CR 608.2b, if all targets of a spell are illegal at the time it would resolve, the spell is countered by the rules and removed from the stack without effect. Your original spell survives and resolves normally.

Note: Veil of Summer only grants hexproof from blue and from black. A counterspell that is neither blue nor black (e.g., a colorless or red counterspell) would not be affected, and your spell would still be countered.

Example: You cast Collected Company. Your opponent responds with Counterspell (blue). You respond with Veil of Summer. Veil resolves, giving your spells hexproof from blue. When Counterspell tries to resolve, Collected Company is now an illegal target, so Counterspell fizzles and Collected Company resolves.