In Superman: War of Supermen comics series, Lex Luthor made our yellow Sun red. All of Kryptonians including Superman & Supergirl started to lose their super powers & became very weak. But, later in the series, it was displayed that Krypto & Superboy were able to fly while the Sun was red.
Krypto is clearly a Kryptonian dog & Superboy inherits attributes of Superman because he is clone of Superman & Lex Luthor. Why was the red sun unable to affect Krypto & Superboy?