how can i see an external reference in one color?
The best thing to do in this regard is to simply go to the layers palette and on the left side of the window, select the reference that you need to change the colour. Now you see on the right side only layers for tat reference are listed. click on any layer name and then select all. In the color, section click on the colour of any layer and change it to any colour that you like to see. when you press ok you will see that all of the layers in that reference are changed to the same colour.