On the 2016 SFOG park map, in the spot where Ninja currently sits, I noticed that the coaster is showing blue track and white supports (instead of the regular red and black). In the attractions list, it reads "The All New Ninja: Coming Late Spring 2016!" The details are vague, but it looks like Ninja will be getting some changes for 2016, with at least one of them being a new paint scheme.
https://static.sixflags.com/website/for ... rk-map.pdf