Technically Shamir's eyes do seem to be gold in TSL. Actually they sometimes seem green, but they're definitely gold. They just don't sparkle. And really, I think that's fine. I think Shamir's sparkle in KQ6 was just to make sure you noticed since the VGA characters didn't have much of a face so it was tough to identify eye color. I think it can be argued that Shamir never actually had sparkly eyes, just that they were gold.
Though if you really want to get picky about it, in the closeups, it looks like Shamir's eyes are all gold, as in no whites, irises, or pupils. He clearly just has gold irises in TSL. But like I said, that's only if you want to get really picky.