Rose Gold reps are known for their discoloration and most of the time members here buy them and send them to our forum watch service for replate. I never have any problem with the yellow gold version, although once I had to reject a QC on the GMT DJ because the gold looked almost copper. I am sorry that this happened to you, it seems like just a small amount is discolored, but on the wrist, it will be hard to see- unless you're specifically looking for it. I know once you see it, it's hard to unseen but it's what it is.
With my gold watches whether it's replica or genuine, I don't clean them with warm water, cold or room temperature is good for me. Most of the time- heat tends to remove the chemical shellacs/ protection on the jewelry. I also don't use any kind of special brush on them- a $1 soft toothbrush works for me. If you have the money and would like to clean your watches, I recommend getting a $30 jewelry cleaner machine from Amazon- fill it up with water- put in the bracelet and set a time for 3 minutes or so then you're golden. I also dry my gold watches with a soft cloth to prevent damaging the protection shells on the jewelry.
However, we are so lucky to have people who can provide the plating service case if you're interested- check out our tech/mod sections.
Best of luck, and I am so sorry this happened to you.
