Change light effect without calling "turn_on"

Would it be possible to set the light effect without actually calling the whole “turn-on” process?

I’m setting up a script which creates a lightning effect when it storms outside. However, it would be really rough if, at night, all my lights just randomly turned on in order to play this effect.

I would like to just set it such that my LED strips play the lightning effect if they were already on. If they were off, they should stay off.

Then just add a state condition to your automation, if the led are on, apply the effect, otherwise don’t.