The last time I went on the Calico Mine ride at Knott's was in 1993 and as I recall then, there was one cave scene but I don't think it had much water in it, I think it was fairly dry. And I think it was rather bright in comparison to the dark Rainbow Caverns. I just watched a Youtube video of it and it is nice for what it is, but they are using a lot of color spotlights, and fluorescent paint on the stalagmites. If Knott's really wanted to, they could build effects more like the Rainbow Caverns by putting in more water features using fluorescent water and black lights alone. They have the enclosed building already built; they just need to add the water features and black lights.
The "tribute" during the first lift on Big Thunder Mountain Railroad, again is nice on its own terms. But it doesn't remind me of the Rainbow Caverns either. They are using a lot of spotlights, colored lights on the water rather than fluorescent water, colored lights on the stalagmites, and even projected moving and spinning shapes on the surface of the water. Nothing like the technique of the Rainbow Caverns which used black light exclusively. And, the daylight that spills in from both ends of the first lift of that ride tends to spoil the effect a little too.
The one thing in Disneyland now that reminds me of Rainbow Caverns is an effect on Splash Mountain, I think about halfway through, there are some green droplets of water that are squirted up a couple of feet by small fountains, and a blacklight makes the fluorescent droplets glow vividly.. the first time I saw that I was instantly reminded of the glowing water in the Rainbow Caverns.
One other thing I recall about Rainbow Caverns was how opaque the water was. You couldn't see the bottom of any pool or channel. They must have used tons of the coloring agent. I originally thought it was milk, that they had added color to. I didn't understand for several years how they created glowing color milk. I learned about black lights mainly from Disneyland and I begged my parents for a black light of my own, and finally I got one for my 9th birthday. I also got a set of 6 tempera paints in fluorescent colors. Of course one of my first projects was to try to recreate the water effect from Rainbow Caverns in my backyard at night, by pouring bowls of water mixed with the fluorescent tempera over little channels I had dug and lined with foil, and illuminated them with the black light. I realized quickly how much coloring agent it required. They must have used huge amounts of the fluorescent pigments to give it the rich colors and opaque, milky look.