I know how to remove rainbow marks from SS - but am I cooking correctly?

Recently bought a tri-ply stainless steel pan, easily my favourite kitchenware purchase yet. I had rainbow marks appear from day one of cooking but a little research told me it was completely safe and I know how to clean it off. I found out that it was likely caused by overheating. All I'm wondering is if it reveals anything I need to improve in my cooking process.

I already keep a shockingly low heat, waiting for the beads of water and checking the oil for a shimmering effect, and by doing this I've avoided a polymerised layer of oil (after my first accident anyway...). I'd just like to know whether rainbow discoloration is indeed very common, even in professional kitchens, and therefore whether or not I need to be more cautious with my heat or another factor.

Thanks so much!