You'd be best with a ceramic heat emitter and a UVB bulb next to the hot side. Frogs need a night time drop so any heater on all the time should be connected to a thermostat to provide the day and night temperatures for species needs. Red bulbs should not really be used as the frogs can see the light, it's just less disturbing than full spectrum light. The dark blue or purple bulbs are okay since it's like moonlight but still any bright light on all night will just annoy them. For night viewing there are blue moon LEDs that can be switched on for a few hours.