That's exactly the approach I started using, after reading that article a couple of months ago, and it's made everything so much easier. There's no more constant tweaking of colours once I have the main palette set, and colours are much more consistent. Before this, I never realised how many colours I actually need.

Following the advice in the article, my current project has six hues, each of which has 9 shades. I really like that diagram of the chat UI that shows all the different colours that were needed.

Yeah, that's effectively the approach I've long taken, though I prefer fewer shades of the accent colors.

What it doesn't help with is choosing which grays and accent colors to use. A slightly warm gray? How does that interact with the accent colors? Do the accents shift hue and/or saturation at the different shades? Doing so usually looks better, but then by how much?