Endura 4 turning a forest green color

[Micahdrake]

I've had my spyderco Endura 4 for about a year now, and the FRN handle is beginning to "fade" to a forest green color. Just wondering if anyone else has had this problem or knows what it could be.
I guess it's not really a problem, I'm just curious.

 

[Kreyzhorse]

Is it fading or dirty? If it is fading, where are you storing, using it at, or cleaning it with?

I've got an orange Delica that has seen a lot but the color hasn't faded.