Mic capsule damaged or not?

[ekwon]

I've got an Oktava mk219 that's about 12 years old now. I like it for what I use it for. But ever since I first cracked it open maybe five years ago, I've seen a ring of discoloration on the capsule diaphragm center connection. I've attached a picture. The discoloration looks various shades of dark blue to purple. Does anyone know the why did it happen and does it matter? If it does matter, should I look into replacing the capsule?
ekwon

 

[darrin_h2000]

Stuff just gets yellow over time...capsules from stuff made in the 50s are still working so It might not matter...but you should keep it in a sealed case with something to keep the moisture away in case you havent allready.

 

[ekwon]

I forgot to mention that 'what I use it for' is stirring drinks.