I remember the days when users could choose colors from 24-bit RGB and whole system was supposed to respect that. Light windows, dark windows, pink windows, anything was possible. Today's big hit is two options to choose from, and it's supposed to be progress.
I just want to say that if/when MikroTik decides to do anything about it, please, pretty please, do it in a way that won't screw it up for people who like current behaviour, i.e. that WinBox uses system colors (to some extent, it's far enough from perfect, but not too bad).