It is almost that except when hdr is on we do the processing in a full screen Post process else directly in the fragment. The main reason being hdr should almost be only a cheap fallback for low end devices. By default it should be turned on as long as possible.
That said the difference of clear color is understandable but yet rather annoying. At some points we were correcting it automatically but then, it was worse in some other cases so we decided to let the user input the value for it.
To find the matching color, you can rely on the toGammaSpace and toLinearSpace functions of the color class.