Colour of borders after build full screen

Hi everybody! So I have the AspectUtility script working nicely. My game displays 16:9 in the editor and once built. I have also set the borders to be a certain colour. This works perfectly in unity but once built for windows and I run the exe borders work but they are pure black. Any ideas how I can force unity to use my desired colour? I have set it to be the colour I require in both the script and the camera background colour. Any help would be much appreciated. Thanks