Using colored ingots (dull copper and up) and choose NOT to use the material color and then smelt that item, you receive only iron ingots back. Same thing with tailoring only when you cut up a NON material colored armor piece made from spined leather, you get back an amount of spined leather that is normal leather colored.
I just smelted a gold shield with Iron selected in the crafting gump, and got gold ingots back. Weapons, unless runic crafted, will always return iron ingots when smelted. Otherwise, they will return the same ingot type they were crafted with, regardless of the ore selection in the crafting gump. Not sure on tailoring but I have seen piles that appear to be plain leather, but are named spined/horned/barbed leather.
I've encountered both of these aswell. Shadow ingots resmelting to iron, and spined leather coming back in normal hue rather than the green.
In what situation specifically have you seen shadow ore crafted items smelting back to iron, other than weapons that are not runic crafted?
