I feel I should make my own style based upon Rainbow so that, on update, I don't overwrite my changes.
 
Starting point:
 
1: have copied the rainbow.css to new rainbowmalik2011.css
 
2: have specified new design - exact copy of rainbow but with the new name -
- so Design Name * rainbow becomes rainbowmalik2011
 
3: Site Navigation
Layout = ALL
 
Now, in Global Settings, if I change Active Layout
to rainbowmalik2011
I get a blank page and the message
Block doesn't exist:menus
 
Clearly I am missing something basic.
 
Chris