Option to bypass all theming and use the system theme/colour scheme

This is likely relevant to all platform.

QtCreator's toolbars and statusbar are painted/coloured by the chosen theme which is, in my case, Flat. And other aspects are managed by the system/platform theme which is, in my case, set by a very fine utility, qt5ct ( a much better version of qt4config for qt5).

So, contrary to all the other (qt5) apps with a unified colour/theme, qtcreator's interface is broken by those oddly coloured toolbars and statusbar.

I use an empty .css to overcome this. Please see the attachment showing the two side by side. Yet it would be finer to give us an option to bypass the colouring/theming and use the system/platform theme as all the other apps do. This may be just an option like "Use system theme).

By the way, changing the colour by Tools>Options>Environment>Color doesn't work because:

1. It doesn't set the colour to my chosen (system) colour but a darker version of it,

2. By qt5ct I've (easily) created some presets and by just a click of the mouse I change the system colour/theme. So every time I should set it by qtcreator>Tools>Options>Environment>Color as well which is very cumbersome.

By the same token, replicating the system colour/theme by a new custom .creatortheme is pointless as one would need to do this for every system colour/theme preset both current and future which in itself is very cumbersome for only one preset in the first place.