Image resize with GDI in .NET gives low saturation
I found the answer myself. It has to do with color-profiles not beeing applied by default in GDI+. Many people claims that you cannot automatically apply color-profiles using GDI, but apparently, the only change I needed to do was this:
using ( var original = System.Drawing.Image.FromStream( new MemoryStream( image.RawData ) ) )
to
using ( var original = new Bitmap( new MemoryStream( image.RawData ), true ) )
Apparently, Bitmap was a derived class of Image, and the constructor for Bitmap can take both a stream aswell as a boolean for "useIcm". That did the trick for me.