To do this you will need the following
KOTOR Tool
.net Framework 1.1 (available at
http://download.microsoft.com/download/a/a/c/aac39226-8825-44ce-90e3-bf8203e74006/dotnetfx.exe)
install both , load up the tool , expand the RIMS line , then the MODULES line
expand kas_m24aa_s.rim
scroll down to p_jolee001.utc
double click on him , youll see a button down the bottom named inventory , click on that , change the iem in his right hand to the saber you want (g_w_lghtsbr01 = blue , 02 = red , o3 = green , 04 is yellow and 05 is purple) save this to the override folder , this means Jolee will play with this saber in the cutscene you first see him in
you will then want to change his other utc file so he starts with the saber you want
thats up in BIFS , Templates / blueprint characters under p_jolee.utc , do the same as above , save to the override folder and your set
or you could just use the save game editor and change it in there :D