From an optical point of view, the main part of the torch is red because?

There are two factors that affect the color of or.

1. Temperature: infrared, red, orange, yellow, green, cyan, blue, purple, white and ultraviolet.

The hotter the weather, the more ultraviolet rays, and the torch temperature is not very high.

2. There are sundries when burning, and different elements will have different colors when burning. I don't know what's in the torch. It's usually natural gas, so the red color is caused by the temperature.