Did you try parallel process?
Use this to shake the screen -
(https://rmrk.net/proxy.php?request=http%3A%2F%2Fi109.photobucket.com%2Falbums%2Fn52%2Fdreamslayer7%2Fbsshot_zps2d10f4c2.png&hash=4d6069bacd2496add89d81e5c111686a24cb8ed9)
Use this to flash the screen -
(https://rmrk.net/proxy.php?request=http%3A%2F%2Fi109.photobucket.com%2Falbums%2Fn52%2Fdreamslayer7%2FHereugo_zps5035a9d4.png&hash=14307bef29e539963bcea1b4e7cd6f84271bcb40)
Just do-
>>Parallel process
> Flash Screen (R31, G31, B31, V31)
> Wait: 1.0 Sec