The colors you linked to are for steel. The e-cat reactor was made of another material. (Alumina)
The report goes into great detail about the measurement methods, calculations, and why they were chosen. I don’t see a reason to repeat them here. I recommend you actually go and read the full report rather than just the abstract I excerpted here.
The visual aids have now confused you?
Here, try this ----http://webphysics.iupui.edu/webscience/physics_archive/colorandtemperature.html
ALUMINA!?!?! WHAT? You've got to be kidding, no wait, the Rossi frauds have got to be LYING. Again.
What a bad joke.