Two different sources suggest that the project is on the way.
According to two separate sources, Sonic Colours could be getting remastered soon for current generation consoles.
The first of these sources is IKSample, a German production company that reportedly works on game localisation and audio. Twitter user @OnTheDownLoTho recently pointed out that the company has Sonic Colours Remastered listed within its 2020 list of credits. The second source is French retailer Sogamely, who has "SONIC COLORS ULTIMATE - LIMITED EDITION SWITCH" listed for $34.99 on PS4 and Xbox One.
Of course rumours like these should be taken with a grain of salt, but Colours does seem like an obvious choice to receive a remaster. Many fans would have likely missed out on the game due to it being exclusive to the Wii, and it's one of Sonic's best received outings in recent memory.