Thanks Solver-- The Help search did lead me to toggle off both patterns and colors, however the resulting views are of grayscale solid-fill images with no lines. The Vector and Technical views give me lines but retain line-drawn textures even with pattern turned off.
This is what Help says: Select 3D> Camera View Options> Toggle Textures in a 3D view to turn off the display of material textures...Not available in Glass House,Technical Illustration or Vector Views.
I'm a new user of Pro. I had assumed there would be a default way to make line drawn elevations, and I have seen what I want in various Home Designer videos. Any other pointers?