I can't seem to find a definitive answer, maybe because everyone's idea of what is blue and what is purple is different. I've seen pics that make it seem blue rather than purple. I recently tested an unknown substance and it went green to the following color. Is this what its supposed to look like? This is the best pic I could come up with, there's clearly a hint of purple but absolutely 0 blue. If it was blue it was only for a split second as it went from green to this nearly instantly:
