It sounds like you’ve managed to get some good feedback on what’s causing it! In my experience, our product won’t change the color of your tack, though I’ve had some folks say that it has worked miracles on dry or scratched tack. I had a customer send me a message with pics of her saddle that had slid on concrete when her horse fell, and cleaning and conditioning with her HSLC made the saddle look like new – we don’t make claims that it works miracles, but I happily share them if the customers say so! 
But, I think contacting Prestige is a good idea, and it is always my first suggestion, as they know more about the leather they use in manufacturing than anyone else does. There are also some products on the market that will darken, and some that are designed to darken, both of which I’ve used myself in the past.
@skipollo I do apologize that the soap has been drying for your tack – that is something I’ve never heard before, and the soap itself has conditioners in it, so that you can use it and only condition with the balm once in a while. Hmmm. Now I’m wondering why that is happening! Also, if you’ve found it too thick for strap goods, it may be going on too thick. My favorite way to use the balm is to let it melt in my hands and rub it on by hand to avoid it going on too thick. And my hands get a deep conditioning that way too 
@LadyB Hopefully, Prestige will have some good suggestions for you!