You haven't stated whether you have the original Virtue code or Redefined code, but in either instance, when placed in programming mode, purple should represent the firing mode adjustment, and even if the colour were changed (a different LED module is sometimes used if the normal one becomes unavailable, or the colour sequence can change if an LED within the module burns out), it is the first adjustable parameter, so no matter what colour the LED module lights up, the first colour represents the firing mode.
First you need to go in to programming mode.
Open up the grip and set DIP switch 4 to 'on' (just to confuse you, setting the switch to 'on' turns the tournament lock off!
Pull and hold the trigger, and then turn the marker on (while still holding in the trigger).
When the LED flashes multiple colours, release the trigger.
You have now entered programming mode.
After flashing, the LED should switch to a solid colour. This colour represents the first adjustable parameter - as already stated, the first adjustable parameter is the firing mode, and this would normally be represented by purple.
To adjust the firing mode, pull and hold the trigger until the LED starts to flash and then release.
The number of flashes lets you know your current firing mode.
When the LED stops flashing, you can then enter the mode you want by tapping the trigger the number of times that represents the firing mode you want - for semi auto, you want to tap the trigger once.
If your adjustment is accepted, there will be a pause, and then the LED will flash multiple colours, then turn back to the colour that represents the firing mode menu (normally purple).
Press and hold the power button until the marker turns off. Reset the tournament lock if needs be. Next time you turn on your marker, it should now be set to semi auto.