It's pretty easy to save them out to a file then restore them later.
This allows you to save different states for different needs.
Below is an example from a layerset, with the following fields:
Layername, state, color, linetype, lineweight, plot style name, is clayer
GRID 67 7 CONTINUOUS -3 Color_7 0
PROP_CORNERS 67 6 CONTINUOUS -3 Color_6 0
plan-siteplan$0$DCA_INFO 66 7 CONTINUOUS -3 Color_7 0
plan-siteplan-scheme1 (5)|DCA_INFO 80 7 CONTINUOUS -3 Color_7 0
plan-siteplan-scheme1 (5)|PROF_INFO 80 7 CONTINUOUS -3 Color_7 0
plan-siteplan-scheme1 (5)|00-VIEWPORTS 80 7 CONTINUOUS -3 Color_7 0
Paul