Currently, if I were to use a single lighting.png skin element in a map, I would be required to skin the whole hitburst skin element set (hit0, hit50, hit100, hit100k, hit300, hit300g and hit300k), as per Ranking Criteria rule:
When skinning gameplay elements, complete sets of elements need to be skinned in order to avoid conflicts between user-specific and beatmap-specific skins. When skinning an element that is marked as optional, you need to include all the required elements of the respective set, but you are free to skip other optional elements unless they are grouped with the element you are skinning. ...I think there should be an exception for lighting.png, as:
- Hit lighting does not interact with other skin elements from the set as much as the others do. For example, it would make sense to skin the hit300.png element if I were to use a particle300.png, while lighting.png is only used to complement the entire set, whatever it may be.
- Hit lighting is one of the two only gameplay skin elements that can be turned off with an in-game option (the other being combo bursts). Players that do not want the lighting element have the option disabled, and they would not be affected by skinning lighting.png.