It seems to me like Sonic's appearance has not changed so much since SSB4. In SSB4, he was based on Sonic Unleashed. While he looks similar to that of Sonic Colors, so does his appearance in Sonic Forces and frankly, almost every 3D Sonic game. Ergo, it's highly difficult to say Sonic is based on one particular Sonic game
Yeah but you guys wrote that his design is from Sonic colors on here[] Cause in SSB4 it said that his design is from Sonic colors so does that mean that his design from smash 4 is still Sonic colors in ultimate?