I currently am working on a drawing that has a floor plan referenced into it and I went into the layer manager and made all of the various layers within that reference file one color. I then saved the drawing, printed it and then closed it. However when I open the drawing up again the layers have all reverted back to their originals colors. It does not keep the changes that I made to the colors. I have to go back into the layer manager and change all the colors back to that one specific color every time I open the drawing. Does anyone have any idea why it will not keep my color changes to those reference files and how I can correct it?

Thanks.