They are adjustable, the fittings can be easily changed out. Pentair has also recently came out with a color changing light that can be added to go through the bubbling water. They can be made the same color as the pool or even a different color.

Have you ever seen 24in spillovers that light up?

Yes, Pentair Pool Products make a fiber optic light (Fiberworks Cascade Light) that can be ran through the conduit under behind or under the sheer descent waterfall. Another idea that looks cool is to mount it under the entire parameter of the pools coping. Another company, Jandy makes a sheer descent waterfall that they sell in 24" with the fiber optic light already included. There are also a few other companies that have developed LED back lights, but I'm not sure the specifics on those. Hope this helps, and thanks for the question!!

thank you for answering the question :)