How do i keep vachetta from getting TOO dark?

I've used apple guarde spray on my Artsy since I got it in June and the vachetta has barely turned .
I did buy it pre owned so I have no idea if the previous owner treated it. But since I've had it, I've wiped the handle with baby wipes ( only alcohol free) & then done my apple guarde spray. It had slowed down the process and even protected the handle. ( now I did get caught in a rain storm and immediately shoved the bag ( Handle first ) under my shirt !!