I should be able to confirm the size of the Red BMW G310R tyres by the end of next week when I take delivery of a new Red G310R. I also did see the change in the Red G310R from the Black on the website but I thought it may have been a graphic change when the Red colour added to the 2019 line up. Why they would change the tyre size is unknown, sometimes manufactures will change the actual wheel sizes in a new years model but there has been no new specs released from BMW. Like all manufactures in the small print of advertising they reserve the right to change the specs. If the Red tyre size is different it will be interesting to see if this change is applied across the rest of colours in the range in post 2019 product.