I have a question.
 

A couple of nights a go a friend and I both wrote a letter to the universe asking for my friendship to be mended with someone. My friend burnt the letter and fire was bright green. Did it mean anything? No chemicals were involved. Thank you for your assistance.

Green signifies Wealth and or Health. I'm not sure how it applies to your predicament. But generally, that is what it signifies.

Green also is the color of the heart chakra. It could mean love or friendliness

My thoughts as well

I'd rather look up for a scientific explanation at this point.