I understand and appreciate brand, identity, marketing, and so on. And based on that experience, I can say with confidence: if your brand needs six colors and shades / tones within each to make a "promise" you need to so rethinking and redesigning. No "promise" that complicated is going to stick.
You began by saying you aren't a trained designer, and ended by telling most of the industry it is doing it wrong. You've come a long way in a short time, congratulations!
As a user of their "doing it right" - and feeling under-satisfied too often - maybe they should be listening more, and imposing their will on the rest of us less? Or do I roll over and play brain dead because I'm told to do so?
I happen to believe less is more. And I've seen that work well / better often enough. If mo' mo' mo' is so great, why am I not seeing it and feeling it?
The very conventional search form for the site I work on has six colors that are obvious including the white background.
I am looking at a picture of an anime character (Kizuna Ai) on my wall and it has two shades of five colors plus one shade of blue used in the background for a total of 11 shades.