Im Sorry but i have question

Im Sorry but i have question

How make a trigger to make unit after enter region CHANGE COLORAnd after leave region Chnage color to Default unit colour is that all POSIBLE ?

make a trigger:

event:unit enter region (your region)
      condition:whatever....
      action:Animation - unit vartex color (then put like 100% 50% 25% <-- something like that, its under animation.
      Run trigger LeaveRegion <-- your second trigger.

2nd trigger: event: unit leaves region (your region)
    condition: whatever....
    action:Animation - unit vartex color (then put like 100% 100% 100% <-- unit normal color.