A white roof or roof coating will reflect more of the sun’s heat so that your attic and your house stay cooler. Flat roofs are especially good candidates, because you can’t see them from ground level. Look for a material with a high solar reflectance. The best ones are usually smooth and white. There are, for example, white roof coatings that can be applied over asphalt shingles and most other roofing substrates.
Terracotta roofs are a familiar sight in warmer countries where the temperature can soar during the summer months. Terracotta tiles are lighter in color than many other types of roofing materials. This means they absorb less heat and are not as affected by the sun as other types of roofing materials. These tiles are baked in a kiln or similar type of oven. This makes them harder and more capable of withstanding different adverse weather conditions.
It helps to have energy saving shingles and lighter colors to reflect more of the suns energy but in my opinion the most important thing is the type of ventilation in your attic. There are many systems but attic ventilation done properly is the most important aspect.
Single Ply
The best roof for a warm environment is an Energy Efficiency Blue Star Cool Roof