HOW CAN SET MY DEAULT BACKGROUND COLOR IN PART AND ASSEMBLY ENVIRONMENT SO THAT I DO NOT NEED TO CHANGE EVERYTIME I OPEN SOLID EDGE. SUPPOSE I NEED SKY BLU EVERYTIME I OPEN A NEW PART OR ASSEMBLY.

You have to change your template part and assembly documents in order to change the background on all new parts and assemblies.

The default location for the template files are c:\program files\solid edge xx\template.

If you open the parts and assemblies in this folder, change them and save it again then it will affect your new Solid Edge documents.