Huy yuy yuy! Such a small question for such a big answer!!!
Change color in WHAT viewing method?
If you want to tint a material in an anlytical view, that is a different problem than for rendering.
If you refer to the 6" horizontal siding: 06 | W Siding - 06" H
whose horizontal lines are created by an image "Lines H Gradient Alpha"
this material is controlled:
For Internal Engine rendering:
-- by adjusting the Surface Color setting in the "Exposure to Light" dialog.
For the LightWorks engine:
-- specify "Match Internal Engine" to have the color change.
It is good policy to never edit a material but make a new one as ej suggests.
Many materials render according to an image mapped on their surface. To change the appearance of these materials requires editing this image map in a photo editor. Lightworks has a built-in way to tint image maps.
OpenGL needs this method to replicate color and will not respond to the internal engine color change method.
.
For color in analytical section views, in the Model Display dialog box specify:
Uncut Elements>Fill Uncut surfaces with: Own material color.
Dwight Atkinson