Short answer: the blue is not burned metal or a failed coating. It is an oxide film that grew thicker as the titanium got hot, and it is the same film that keeps the metal from corroding in the first place.
What is the colour, physically?
Titanium reacts with oxygen as it heats and builds an oxide layer on the surface. That layer is only tens of nanometres thick, but light reflecting off its top and bottom faces interferes with itself, and the wavelength that survives shows up as colour.
The sequence as temperature climbs runs straw, bronze, purple, deep blue, then a pale grey-blue. A mug used directly over a flame rarely heats evenly, which is why one piece can carry three colours at once across its base and wall.
Is it damage?
No. The film is the passive layer that makes titanium corrosion-resistant, thickened by heat. It does not flake, it does not rust underneath, and it does not change the weight, the taste of the contents or the food-safety story.
What it does change is appearance, which matters more to a retailer than to a camper. A display unit that has been demonstrated on a stove is no longer a uniform colour, and that is a merchandising decision rather than a quality one.
Why do anodized pieces behave differently?
Anodizing is the same oxide mechanism run deliberately: the layer is grown to a controlled thickness in a bath, and the thickness sets the colour. 305 of the 503 SKUs in this range are anodized on that basis.
Because the colour is already an oxide layer, more heat does not create colour from scratch - it pushes the existing layer further, so a blue piece drifts rather than turning gold. The 53 crystal-labelled finishes carry no scratch or fingerprint claim at all, which is a separate and deliberate choice.
Can you take it back, and should you?
Mechanically, yes: an abrasive pad or a light polish removes the grown film and returns bare metal, at the cost of the brushed or blasted texture underneath. Chemically there is nothing to strip, because there is no coating.
The practical answer for a trade buyer is to choose on purpose. If the piece will sit on a shelf, specify an anodized finish and keep it off the demo stove; if it is a tool for fire use, the colour change is part of what the customer is buying. MOQ is 5 pieces per SKU, samples in 5-10 days, stock orders out of Baoji within 72 hours.
Want prices, samples or a custom titanium line?
MOQ from 5 pcs, ships within 72 hours, replies within 24 hours.