We use this Bissell cleaning solution with our portable carpet cleaner. It's never caused any fading on our furniture or cloth car seats. The back of the bottle does say "For upholstery, use on manufacturer's code "WS" or "W" only." What ever that means, but this stuff works. After using it, I spray on fresh water as a rinse and draw it out with the machine.
Mainly for the carpeted floor mats, but on occasion the carpet under the edges of the floor mats. Just have to use a minimal amount so it doesn’t soak in, then wipe it up really good with a slightly damp towel, followed by a dry towel, then open up all the windows so the carpet can dry out.