Weirdly, BB goes on about the meth being blue because it's so pure. But the original batch of blue speed was cooked by someone I met back in the late 80's.
The scene: Riverside County, CA. Once the official fount of most meth labs in the US. Because, desert. Miles and miles of it.
Apparently, the other cook in this instance accidentally knocked a jar of blue toilet cleaner into the bathtub where the meth was being made. They decided to charge extra, and called it 'Australian Blue'.
Apparently, people were convinced it was somehow better than the usual, and went nuts trying to score more of it somehow.
I rather suspect that this incident became the inspiration for the BB storyline. Because writers and Southern California and Hollywood. If you live there long enough, you WILL eventually know some of those in that either industry.