Most likely you have Display plot styles checked on in your page setup.
In your page setup dialog, look under the Plot Style pull down. Uncheck it if you want the actual colors of the objects to show.
Autodesk Knowledge Base:
ID: TS53144 - Monochrome Vectors display option is no longer available
Paperspace entities turn all white
Display in Paper Space
PaperSpace view Issue
Problems with colors showing up in a layout!
LDD3, 2002: layout shown in white
Layout Tab displays no colors
Different Colour in Paperspace
Paperspace display is black and white Only
Plotting and layer colors
Drawings displays as white in Paperspace.
Layer Colors change in Paperspace
Insert colored items in Paperspace they come out black
Layout, Xrefs, Viewports All Color White
Everything appears White n Paperspace