There's no coating to come off. A plain stainless pan is bare steel right up to the cooking surface, and the rainbow comes from the steel's own thin surface layer, thickened by heat.
It usually shows up after the water test, when a new pan sits empty on high heat and the inside turns gold, copper or blue. The pan cooks the same either way.
Why does stainless change color?
In short. Heat thickens the thin oxide layer that's always on stainless steel, and the thicker film bends light into colors.
Stainless steel always carries a very thin oxide layer on its surface. Heat a dry pan hard and that layer gets thicker. The British Stainless Steel Association puts it down to "progressive thickening of the surface oxide layer," with the colors made by light interference.
The association adds that in some industrial uses heat tint can affect corrosion, depending on the steel and the setting. For a pan, makers treat it as cosmetic. Heritage Steel's care guide says the pan cooks exactly the same with or without it.
How do I get it off?
In short. A paste of baking soda and hot water, or a powdered stainless cleanser, worked in with a damp sponge.
Mix baking soda with just enough hot water to make a gritty paste, work it in with a damp sponge, then rinse. A powdered stainless steel cleanser does the same job. Or leave it, since 360 Cookware puts discoloration down to persistent overheating, and it'll likely come back if the pan keeps meeting high heat.
Some streaks are food, not heat. Cristel's FAQ says rainbow streaks can be deposits from food, and lists white vinegar and baking soda in very hot water among the ways to lift stains. Our stainless cleaning guide covers the rest.
How do I know my pan has no coating?
In short. Check what the maker states, since a coated pan's maker names the coating.
Coated pans come with a name for what's on them: nonstick, ceramic nonstick, enamel. If the maker says the cooking surface is stainless steel and names nothing else, there's no coating to lose. Our cookware material lookup lists what 43 pan lines state about theirs.
Got a pan with a mark you can't read? Send us a photo.
Sources
- British Stainless Steel Association, Heat tint (temper) colours on stainless steel surface heated in air. bssa.org.uk. No page date shown; read 2026-10-31.
- Heritage Steel, The 3 levels of cleaning. heritagesteel.us. No page date shown; read 2026-10-31 (maker statement).
- 360 Cookware, Use and Care Guide. 360cookware.com. No page date shown; read 2026-10-31 (maker statement).
- Cristel, FAQ, I see traces. cristel.com. No page date shown; read 2026-10-31 (maker statement).
- Clearly Made, Cookware material lookup, maker pages read 2026-10-30. clearlymadegoods.com.
Last reviewed October 31, 2026. Spot an error? Tell us and we'll fix it here.