old discoloured blades

[Vrael]

Hi, I have one question about old blades. Why some of them have nice colour and some of them are discoloured as hard as this one ?
Does it have any impact on performance and if yes then what is it ?
Example of 2 keyshots light, 1 discoulored pretty hard and other one has "good"/original colours

 

[Tyce]

First thing coming to mind is interaction between lacquer and VOC glue.