Successful clamping without discoloration?

Hi!
After long break, I’m trying to back on track and improve my results. Until now I made only manual exercises, so I decided to to take PE on another level and incorporate clamping to routine.
I’m preparing to this for few days by making short sessions of clamping using two fingers in OK grip and taking observations how my unit react. I noticed that after 1 minute of clamp skin just above fingers becomes temporally dark brown in few places. Maybe I’m pressing with too much pressure? I’m aware that every exercise brings the possibility of injury, but I want to develop clamping routine which is maximum safe for me.

I wonder whether there are some guys that gain at least 0.2” girth using clamping techniques and didn’t get any discoloration? Any tips from you guys?

I’m also curious about the patterns causing discoloration:
1. When discoloration occurs - if it happens straight away, or after few workouts, when tissue is really fatigued.
2. Pressure as factor. I guess the more pressure, the more chances to end with dick looking like a rainbow. How about short sessions with low pressure, whether they can cause similar negative effects?

Any answer is welcome.

I’m very interested to hear some replies.

With a proper warm up I’ve managed to avoid most discoloration, not total though. Start slow and warm up with a rice sock. If it bothers you search for threads on removing discoloration. I know some people have had a good amount of success with it.