Questions regarding color problem in AutoCAD Mechanical 2007

Hi everyone,
In AutoCAD Mechanical 2007 I'm having a problem with colors. When I change the color of a 3D solid model part within an assembly, save the
drawing, then open the drawing again, the part seems to revert back to previous colors that were used during the design process.
Sometimes, a part is even more than one color, one surface may be blue, another surface may be red, etc.. It seems AutoCAD is *remembering* all the colors that I tried or used throughout the design process and is somehow getting confused as to which color was the last saved color.
The drawing has a fair number of layers and I wonder if the issue is somehow related to layers. If I type the layer command and change the color for the part there, and then go to "object properties" and choose "by layer" as the part color, it does not help. Additionally, if I actually choose for example *red* from object properties, I still have the problem.
I can change colors fine while the drawing is open, but when I save the drawing and reopen it later, some parts are either not the color that was last saved, or some parts have several surfaces with different colors (colors that were used or tried throughout the design process).
It may be worth noting that when the drawing opens, for the first few seconds the colors seem correct, then a few seconds later, the colors of certain parts within the assembly will change.
When you add or subtract to or from a solid model part, does the portion that is being added or subtracted have to be on the same layer and/or be the same color as the part that is being modified ? I never had to worry about this with previous versions of AutoCAD but perhaps something changed.
I would appreciate any ideas or suggestions anyone may have.
Thanks John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.