@<Inkscape> Ah, that makes more sense. I was always told it was blue > red in terms of flame heat. I guess it could be a chemical factor from the Mega Evolution if that were the case then, as I believe hormones can influence the color of flames to a small degree.
@Merciless Medic
not neccesarily
While the spectra of the fuel and any added chemicals influences flame color, so does incandescence. Incandescence is the emission of light as a function of temperature (black-body radiation). From coolest to hottest, incandescent flame colors are red, orange, yellow, and white. Incandescence begins to become visible as a dark red glow between 500 and 600 °C and reaches a white flame around 1400 to 1600 °C. Blue also occurs sometimes, when there is a low amount of soot. While blue is relatively uncommon in campfires, it often occurs in welding metals.
so based on this
unless charizard is really soot free
he should have white flames
XD Blue fire indicates a hotter flame, which means Mega Charizard X has a more potent flame compared to Mega Charizard Y and Charizard, among other Fire-Types and Fire-Type users.