Thanks huggyg71. Tried the first site but this seems to concentrate on changing the title of the start button rather than the colour. Liked some of the "skins" in the second site, downloaded one which, when unzipped, appeared as a file. I opened the file but couldn't understand how to set it up and run it as a "theme".
Using Resource Hacker, I went thru the procedure to alter the text only on the start button,rebooting failed to complete loading desktop.On checking,I kept getting the message "This is not a valid win32 app" I tried both ways(regedit in one post and no edit neccessary in another)Fortunately,I could still Ctrl-Alt-Del and run regedit to access the changed key,and return the original Windows "explorer.exe" from whence it came,all from Task Manager.