Okay so I downloaded an animated gif from the interwebs.
I want to edit this gif and open it in Photoshop. Like I expected there are 481 layers.
I want to change the background color :-)))
Can I do this in a quick way? or do I have to edit every layer?
If the color adjustment is "simple" and not complex. ie a single color. You can create a top layer color adjustment (Hue/saturation or color balance.).
You would basically keep this layer visible the entire timeline, for every frame. It really depends on the complexity of the gif frames. If the background stays the same you could apply/edit the adjustment layer mask too to omit the actual animated part. This would likely mean the background color you are referring to never changes shape.