Possibly...
If the bearings were smoking hot the hub would have to be very hot enough to transfer heat to the axle flange. (the wheel bolted to the hub would also be really hot) If that happened I'd suspect the entire axle flange in contact with the hub would/should see the same temp and color change That is not what's shown with the outside portion of the axle flange being cool, no color. The color pattern indicates the axle shaft was the hot part and the heat didn't quite travel out to the outside of the flange.

I'd guess the colors on the axle shown are a result of the manufacturing process, tempering, and not an indication of previous severe bearing trouble.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-