Those "vacuum pumps" dont create anything near a true vacuum, I sometimes use them on my wine and they pretty soon will make a click sound indicating the overload valve opening to prevent failure. Creating a environment emptied of every last molecule is near impossible and very costly, like when you wanted your own mass spectrometer or idk.
The other question is: In the ambient condition you can achieve with that device or in a true vacuum, would you gain anything ?
Proof of what is causing the discoloration would be helpfull, sadly I dont have any exact and true proven knowledge here but in general, if its the presence of various gasses that cause it, I have the unproven opinion its oxygen / oxygenation, you wont get something from a wine pump, but from a turbine pump with attached molecule trap
Other considerations that should be made, and for me that would be the most worrying and the reason to not make a habit out of the wine pump if it doesnt give you a clear advantage: The perhaps rising chance of sublimination
Crossing all minoe effects out I strongly feel you wont gain or loose anything with the wine pump, but I am interested on your findings and if they are special, finding a good explanation.
Give it a try.
Maybe a more easy route would be to flush your container with N, CO2 ... anything cheap and available.
The Bavarians are an uncouth but sociable folk, they would prefer have wood hacked on them rather than be brought to a state of rebellion; but if you should seize or spoil their beer, they will revolt more wildly than any other folk.
QUESTION: What common materials are soluble in acetone?
ANSWER: Styrofoam