Because my Nightengale hood has changed colour to white.

I kid, I kid. As sure as night follows day i'll buy it on release day. It is annoying though and my guy looks considerably less badass.

Have you tried reloading saves and dropping it and re-equipping it? That'll probably fix your issue. If not, I don't know what you should do.

It sounds like a texture glitch, just try what daStig mentioned.

Tried an earlier save from before it changed and also dropping and requip. Read somewhere that dropping it and travelling to another cell then returning for it can fix it, will try that later.

I wouldnt mind but the other Nightengale's hoods have done the same, so I cant even RP that i'm some super Nightengale who wears a different hood lol