The reason behind not wanting the red light is because during the day it can make things look distorted. They're used to being outside in bright white sunshine so that's what we should try to simulate. At night, visible light can disturb their sleep so it's best to go with a purely infrared option if needed so no visible light is emitted.
It's great that you're using the Herpstat. I have the same one and it works really well for automating the temperatures. If you're having trouble keeping the temps up, I'd try a slightly higher wattage bulb or a different type. I use a PAR38 halogen flood light in my setup and it handles dimming from the herpstat really well. I have that over the basking area and I have a MegaRay heat projector bulb over the cool side. One probe sits in the basking area and controls the output of the basking light via dimming setting. I keep that set between 100-105 during the day. I have the second probe on the cool side floor and that controls the heat projector bulb which is on pulse setting. It kicks in at night if the temperature drops below 70 and it turns off at 73 or above so most of the time it's not on.
My
UVB light is on a mechanical outlet timer and clicks on about and hour and a half after the basking light ramps up and goes off about an hour before "sunset".