Thank you so much for taking time to post :)
Hi and welcome,
I'm not sure if you meant your question to land in the MS community forum or not but what you've describe would not be a typical symptom of MS.
If your hands are loosing their normal colour and your feeling pin's and needles when they are normally hanging down in a relaxed state but go back to normal again by changing their position, to me that does sound a bit of an abnormal response basically because it's the opposite of what should be happening.
If it was just the pin's and needles i'd be thinking along the lines of a pinched nerve but with the colour change too, which is usually connected to impinged blood flow and its happening in both hands, then i'd be thinking there could be a spinal issue causing it to happen, it's something i do think you should see your doctor about.
cheers.........JJ