Soldier TF2 - Resources
Quick Notes - Pyro
Pyro does not have a known name, or a known gender. Pyro is generally referred to with he/him, or using non-gendered pronouns - although the captions on some videos also use she/her on occasion. Pyro is the second-shortest merc, and their build is primarily obscured by their suit, although it seems vaguely rectangular.
Resources
Fire Colours by Temperature
This guide is in a truly awful jumbled-up order, but it lists all of the possible colours, unlike some which cut off at standard wood/wax fire temperatures.
Fire Colours by Metal Additive
A nice little creative-commons poster. Wikipedia also has a decent chart with some images.