[Munch]

Without editing the sp to cycle through the colours, the best you can do is add this to your autoexec.cfg

//FLASH LIGHT (repeated presses of "L" cycles through colours)
bind "l" "fl"
alias fl "fl1"
alias fl1 "sm_light white; alias fl fl2"
alias fl2 "sm_light red; alias fl fl3"
alias fl3 "sm_light orange; alias fl fl4"
alias fl4 "sm_light yellow; alias fl fl5"
alias fl5 "sm_light green; alias fl fl6"
alias fl6 "sm_light blue; alias fl fl7"
alias fl7 "sm_light purple; alias fl fl8"
alias fl8 "sm_light off; alias fl fl1"