I wonder if you could mostly have white spray paint and tiny cans of color. When I've seen paint mixed it's usually a surprisingly small amount of color being mixed in.
It's almost certainly possible, but when I've had cans of paint prepared (which, admittedly, was twice ever), they've always told me to get slightly more than I think I need because mixing a second batch that attempts to be the same isn't guaranteed to look the same when it dries. Still, if there's a continuous feedback mechanism like in this article, perhaps that's no longer true.
(Or perhaps it wasn't true even when the shop told me, and they were just repeating some second-hand knowledge that was last true a generation earlier; I wouldn't know).
It's almost certainly possible, but when I've had cans of paint prepared (which, admittedly, was twice ever), they've always told me to get slightly more than I think I need because mixing a second batch that attempts to be the same isn't guaranteed to look the same when it dries. Still, if there's a continuous feedback mechanism like in this article, perhaps that's no longer true.
(Or perhaps it wasn't true even when the shop told me, and they were just repeating some second-hand knowledge that was last true a generation earlier; I wouldn't know).