I was moving my tank today (so I emptied out most of the water) and when I turned on the lights after it was setup again I noticed most of the hair algae on the back of my tank went from a light brown to white.

Is it dead, or is it just in shock or something?.

If its dead do I need to remove it, or will it be fine left alone.

I thought you had zero problems. Just kidding.

I think that you should manually remove the algae whether it is white, tan, green, or whatever. Usually when algae turns white, it is going into a reproductive stage (releasing spores) in a last ditch effort to try and save itself. It can be a good sign if you are in the process of manually removing it and reducing nutrients (it tells you that it is lacking something that it needs to live), but it can become an issue if nutrient levels are allowed to increase again (potentially returning even heavier than before).

Thank you for the advice. I don't consider it a problem because it is not overtaking the tank. It's sitting on the very back of the tank and honestly it looks cool with the wavy effect it has .

It was lacking water, since it was exposed to air for a while!. I just blew the white algae off, the living stayed put. It all got sucked up into the filter floss .