I wouldn't knock leds before you try them. A simple, calm color can be really nice for almost anyone. My wife doesn't play games at all but has a nice aqua blue glow under her keys that she very much likes. I suspect that's actually what most people use, even if the keyboard supports psychedelic funky patterns - which hers is totally capable of.
I like the Ducky keyboards as a nice middle-ground between price and functionality. The Ducky One 2 comes in just about every size/variation and has plenty of lit and unlit options. Search up the "Ducky One 2 Midnight Double Shot PBT Mechanical Keyboard" for an absolutely serious, no-frills black keyboard. They also have unlit boards with color-coded keys. Your main alpha and numpad in white, other keys in black/blue and sometimes return/space or other keys in a brighter color. Still, I really do recommend the leds. Set them to a soothing color in low intensity and you'll probably be very happy.
Pure typists typically use a more tactile switch with a bit of feel to it, typically the brown category switches, but if you want a pure linear switch go for red or black. Probably black.