To be fair, I don't mind case lighting, side windows etc.. and I don't really mind RGB (to an extent) - I have a NZXT Hue+ but I can't remember the last time I used it. I just hate the "RGB everything" bandwagon that just about every manufacturer has jumped on - it feels like a substitute for quality, and a lot like the 3D movement in film making - "it's awesome cuz it's 3D".
I had a K65 RGB board and after piddling around for an hour making fancy patterns, I ended up setting it to a dim white back light, because that's my preference. I ended up selling the RGB board and going back to my QF Rapid-i with it's white back light, because it's a better board.
I also have RGB LED strips taped to the back of my monitor and run as a back light to mitigate screen glare (it's dark in the man cave), but they're set to a single colour and run off my monitor's USB power.
Not sure if my mouse is RGB - never checked, but I don't care enough to find out.