Idea for new Razer chroma effect

I had an idea for a new effect for the chroma studio. When you press the FN key on a razer keyboard, it lights up all of the function keys that apply to it. I thought it would be cool if we could use this effect in studio. I.e., it would be cool if we could have a function like reactive, but instead of lighting the key that was pressed, it would light a different key specified by the user.