More energy it absorbs. A solar panel is typically dark too, but it not just absorbs the light, around 20 % of it gets converted into electricity. A dark tile don't produce electricity but just absorbs the light. The ammount of energy you need for AC depends on the insulation you use - a well

Insulated building takes very little energy to stay cool. A typical Australian Sydney House however with single glazed sliding windows is energetically poor compared to European buildings and consumes far more energy for AC to stay cool.