I just got a new LG stove gas with 2 ovens and convection bake. It has the blue porcelain interior. I cooked a pot roast which spilled over. I mopped it up with paper towels while cooking and then wiped it out after it cooled. Used soap and water to clean up the mess. It came off easy but left a hazy rainbow color behind. I have tried running the self clean, using vinegar, and separately using soft scrub. The haze is still there. Is there anything to get this off or am I just stuck with it?