Looks like an original J. P. Sauer & Sohn made High Turret sniper rifle. And if this is not enough, it is scope matching numbers. Are all other numbers matching too? I noticed it has a walnut stock as well, not laminate.
The yellow color might be due to the fact that it seems most of the finish is lacking from the rifle (on many parts even looks like it was sanded off). Adding to that is bad light conditions and possibly artificial flash plus wrong white balance.
If you take the pictures again, please bring the rifle out during daylight, best on a cloudy day. This will make a huge difference. While taking pictures make sure to take an overall picture of the whole rifle from both sides, then from the action with the scope visible in full length also from both sides before getting into certain detail aspects.