Similar to the red shields, there are a few doorways that are showing up with an orange shield around them. I have seen this around some chests too. How are you meant to destroy these? The sword attack does nothing and no other weapons seem to damage it either. It only seems to be on chests and items that are not critical to progression so I feel like I am missing something here.
The orange shields are the upgraded version from the red shields. To destroy them, you need to get the upgraded melee attack. You can find some artefacts that will upgrade the sword or you can purchase the upgrade using obolites. The shields are not very common though so I never bother going out of my way to get the upgrade.