system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When you make red hot metal hotter, why does it become white hot, rather than blue hot?
gpt
Color temperatures go red->orange->yellow->white->blue.

It could become blue hot if you mad it much much hotter. But in practice you can't make iron hot enough to be blue hot.

6500 K is "standard white" (color of sunlight).

You'd need to make it around 8000 K hot to be blue.  
Iron **boils** at around 3000 K.  
Even tungsten boils at around 5700 K.  

So any metal you could be heating up would boil away before it became blue hot.