I have no idea how to script a lighting change. D:

[kaecyus]

I don't have access to change the Windlight settings on the parcel, either through the sim-wide default or through the parcel description. However, I would like to give people the opportunity to swap to another Windlight setting (specifically [NB] Aftermath 0000), through a script, whether through something embedded into an option on a greeter, or a clickable object that would change it for them if it had permission to do so.

Does anyone have any thoughts on how to acheive this?

[Innula Zenovka]

If they are using a third-party viewer that supports RLV and they have RLV enabled, then it's easy enough to do with @setenv.  

Otherwise, no, there's no LSL commands that would help you, I'm sorry to say.

[Nova Convair]

- Viewer settings can't be changed by script.

- I doubt that many avatars would give your script a permission for RLV even if it's only the windlight

- You can add this line to your parcels description:

/*Windlight Sky: "[NB] Aftermath 0000"*/

All avatars with TPV's (Third Party Viewers) that have automatic windlight active will switch to your setting then. No LL viewers. Works only it that windlight is present - so exotic ones and selfmade ones are no good choice