How do I generate random numbers in batch and turn them into variables to set the color?

This is the script I tried that didn't work: @echo off :start :randomcolors echo Warning: 1/30 chance to crash pause>nul cls set back1=null set back2=null set back3=null set back4=null set /a integertype=%random% %% 2+1 if %integertype%==1 set sys=# if %integertype%==2 set sys=str if %integertype%==1 set /a back1=%random% %% 9+1 if %integertype%==2 set /a back2=%random% %% 6+1 if back1=null goto skiprc set color 2=%back3% goto skiprc2 :skiprc if %back2%==1 set %back2%=a if %back2%==2 set %back2%=b if %back2%==3 set %back2%=c if %back2%==4 set %back2%=d if %back2%==5 set %back2%=e if %back2%==6 set %back2%=f if %back1%=1 set com1=1 if %back1%=2 set com1=2 if %back1%=3 set com1=3 if %back1%=4 set com1=4 if %back1%=5 set com1=5 if %back1%=6 set com1=6 if %back1%=7 set com1=7 if %back1%=8 set com1=8 if %back1%=9 set com1=9 if %back2%=a set com1=a if %back2%=b set com1=b if %back2%=c set com1=c if %back2%=d set com1=d if %back2%=e set com1=e if %back2%=f set com1=f :skiprc2 :part2 set /a integertype2=%random% %% 2+1 if %integertype2%==1 set sys=number if %integertype2%==2 set sys=string if %integertype2%==1 set /a back3=%random% %% 9+1 if %integertype2%==2 set /a back4=%random% %% 6+1 if back3=null goto skiprc3 set color 1=%back3% goto skiprc4 :skiprc3 if %back4%==1 set %back4%=a if %back4%==2 set %back4%=b if %back4%==3 set %back4%=c if %back4%==4 set %back4%=d if %back4%==5 set %back4%=e if %back4%==6 set %back4%=f :skiprc4 if %back3%=1 set com2=1 if %back3%=2 set com2=2 if %back3%=3 set com2=3 if %back3%=4 set com2=4 if %back3%=5 set com2=5 if %back3%=6 set com2=6 if %back3%=7 set com2=7 if %back3%=8 set com2=8 if %back3%=9 set com2=9 if %back4%=a set com2=a if %back4%=b set com2=b if %back4%=c set com2=c if %back4%=d set com2=d if %back4%=e set com2=e if %back4%=f set com2=f :action color %com1%%com2% pause goto action