The rerason is, that the RAW RAF file is not an image per se. It is sensor data. To display it, the data has to be interpreted into an image.
This is done by a piece of code and takes a little while. Being interpretation, the result may differ between programs.
What you see in Windows is that the explorer or most editors shows you a low-res jpg which is ...
I always do the color grading stuff before, because if done after retouching it can make the editing more visible. The edited parts are always a bit different from their surroundings and will react differently to the color tools.