Yeah, just one.
I think it is a little deceiving as to how much light is given off.
This is a little more true representation. Room lights on and dim, white cage LED light on as well.
You can see it does not over power the regular cage LED light.
Just the blue in this shot but I think I have 1 room light on as well. I had to enhance the picture here to get more light to see the boa.
Maybe for the decent prices go with blue and red. Mix it up for fun!