can you double up on lamix? ex a yellow layer with a blacked out layer on top. To make the output yellow but hide the yellow film when lights are off?

That would change the color of your output, as well as drastically reduce the amount of light that comes out.

it would just look like a darker yellow when off.

why not just use yellow bulbs and smoked lamin-x so that you get yellow output that looks smoked when off?

+1

I know it's not a problem with E36's, but I recall on a Honda FG forum (2006+ Civics) several people reported the Lamin-X getting burnt since their fogs emitted more heat than most fogs. There is now a warning for FG fog specific Lamin-X not to double up on it.

Again, this shouldn't be a problem with E36's, but I would also recommend just smoking them and running yellow bulbs.