The hazy rainbow tint you're seeing is very common with new stainless steel cookware—it usually appears within the first few uses. Luckily it can be easily removed by following one of the methods below:
- Dilute a little white vinegar (e.g: ⅓ cup water and ⅓ cup white vinegar) and pour it into the pan. Let it sit for a second, then wipe with a non-abrasive sponge, rinse, and dry.
- Use a little Bar Keepers Friend mixed with water (a mild oxalic acid), which will make the calcium deposits dissolve. Rinse and dry.
For context, this haziness is caused by calcium carbonate found in water, and the rainbow effect is oxidation caused by the small percentage of chromium in the stainless steel (which is there to help it resist corrosion and rusting). It has no impact on the product or performance and again, will be more noticeable and/or appear more frequently when your pan is still new.