Hmmm... Black tub with the red light may not be a good choice in My Opinion.
Black absorbs and hold heat and you could have an issue with over heating.
Think of this - Walk outside on a warm sunny day bare foot, The light colored side walk will be warm to your feet but then step onto the Black Asphalt next to it and it will be hot. Black/Dark tends to absorb and hold heat, White/Light tends to reflect heat.
You could end up cooking your new little bumble bee...
Roasted Bumble Bee is just not a dish I am interested in trying...LOL
The size you mention should be fine unless you are talking about a larger sub-adult / adult ball python.