How deep is your tank?
At only 36 watts, it's pretty weak. Sorry for the bad news.
Here is what Reef Builders said:
We tested the 48″ Coralife LED Aqualight S over a 75 gallon aquarium and found that it lived up to the claims of roughly 40 umols of PAR at 12 inches underwater. Since 55 and 75 gallon tanks are 18 inches deep, you’ll get lower light levels beyond 12 inches so with a single fixture you’ll manage to grow coralline algae but on shallower tanks you could conceivably keep and grow low light corals.
So if your tank is more than 12" deep, I'd suggest 100% blue, and as close to 100% white as you want (the closer the better), and whatever you want on the RBG channel.