* Sulfur Dioxide (SO2): When sulfur dioxide dissolves in water, it forms sulfurous acid (H2SO3), which is acidic.

* Universal indicator in acidic solutions turns red.

* Carbon Dioxide (CO2): When carbon dioxide dissolves in water, it forms carbonic acid (H2CO3), which is also acidic.

* Universal indicator in acidic solutions turns red.

Therefore, both sulfur dioxide and carbon dioxide solutions would turn the universal indicator red.