Your question has been much debated (sometimes even seriously and others just hot air). Here is one link with both strategies. https://tw200forum.com/forum/general-...-wanted-2.html
It comes down to changes in carbs, brakes in front; kick starter lost, and an iffy electrical system on the 1987 model year. Read and filter some of the opinions about red being faster etc. You can determine the exact years that these changes were made, and its not that many, but you may have to look at several threads to get the entire picture.