"I really don't care for" as in I don't really like.
Sorry, I didn't now about this meaning in english.
This works and will be fine for its purpose but if there are other popular methods I would love to compare/contrast.
This is by far the best method for what you want to achieve. As I already said, it's simple and efficient.
The "venn diagram effect" is not an issue. If you have lights that overlap, you really want their contributions to be added. This may not be obvious here, but think about a red light and a green light: what would you expect the overlapping region to look like, if not yellow?