Originally Posted by Galloglaich
There has been some debate if lacquering was ever done in Europe but there is no evidence of it that I know of.
There are countless depictions of helmets in bright colours. Those at least were pretty obviously painted or lacquered in some way, even if it was just for the looks it would give significant protections against the elements.
For rigid armours, something similar would be possible even though I can't think of any sources on it actually being done. On the other hand, there are depictions of mails ranging from bright pink through baby blue to black, I'd like to know if they actually did that -and how...