You are correct... They havnen't always been black... (judging by this photo)
However, the padding just Velcros in place... So it may be something that DW had been planning on changing because how quickly non-black colors start turning black (See Diamondback at Kings Islands headrest) so maybe they just changed out the Velcro pads while they were making other modifications!
¯\_(ツ)_/¯
Then again, I could be completely wrong! Only time will tell! -------- Personally I'm just glad the freaking ride is finally testing again!!