"Brown" is just very dim orange. A pyro buddy of mine told me a story about a group discussion that started about the possibility of "brown" fireworks stars for aerial shells. There is no way to do it directly. The way it was finally achieved, someone built a shell with a mix of brilliant white tailed stars and regular orange stars. In the air, the brilliant white made the nearby orange stars appear brown. A relatively dim orange laser spot amongst several bright white ones would appear much the same way.
2c,
T.
I thought this thread would end all the others. I was wrong.