Using 150 grit sandpaper on GEC Micarta 71 Bullnose

[sunandsteel]

What would be the result of using 150 grit sandpaper on my natural micarta 71 Bullnose?
For some reason, when I'm using the knife or if it sits in the sun for a short period of time, one side will remain lighter than the other side for a longer period of time. This also happens if it gets a little wet from my hands. Also noticed one side just a little more shiny than the other.

 

[Steve Lawrence]

I use 400 grit sandpaper on my bullnose regulary it puts a nice mat finnish on the micarta good and grippy