3D solids all plot in Gray

[lholt]

I am attempting to plot a map containing 3D Solids. ALL solids plot the same shade of gray. Blocks and paper space objects plot correctly. The plot style is acad.ctb (not edited). Plotter is HP-DJ800-HPGL2. All colors & linetypes are set to By Layer.
I have exhausted my meager knowledge & am thoroughly frustrated. all help is appreciated.
Thank you
-Larry-

[Jmurphy]

Check the properties of the viewport and the values for Visual Style and Shade plot.