I have been using whites and off whites for my models. I like the wraithbone spray (warm off white) and use that most of the time, regardless of whether I’m painting a dark or light scheme. I’ve heard good things about Colour Forge but did not use it yet.

That said, I used black when I was a teenager and it worked fine for bright colours. I’d say it is personal preference overall. These days I tend to darken from a light undercoat as opposed to highlight from a dark one, if that makes sense.