rgb colour analyser

Hi all...although I have jumped into the hobby electronics hobby recently, I am also an aquarist. I have kept fish for many years. I had an idea to merge these two hobbies...I wanted to analyse the aquarium light and measure the RGB values in terms of their Kelvin value. Because different plants and corals require certain blue and red values, I think this would be something that would be an excellent tool. I love the idea of it being portable, like with an Arduino. I know the 9660 sensor/rgb module can measure the percentage of red, blue, and green from a light source, but does anyone know how I could either measure the kelvin values, or translate the rgb % values into their kelvin values?
Thanks for any ideas!!

The problem here is that real light is a continuous black body radiation distribution. Using LEDs replaces that with three narrow frequency bands. So because of the way the eye works you can trick it into thinking that you are looking at a specific temperature black body radiation curve.

How do you know that fish and corals will fall for the same trick? It seems unlikely that they perceive coloured light in the same way. My guess is they actually need those higher frequencies of light not just the look of it.

There are a lot of color sensors out there, but you'll have to do some research to figure out which one works best for your needs. Hopefully it isn't the $2,000 sensor :o