Back in 2001 Hank Is Here posted this: "I know there was white in 87. I have an 87 parts coupe that is white."
There were 34,211 white cars produced over 5 years. White was available in all years. 23,603 base coupes and 3875 SE's and 3135 Sports in 87. I think the Sport was actually either the 4-cylinder or did they retain the bumper pad into 87? Certainly, there were white ones made with that total quantity.
Another less reliable source says white was only available in 84-86 but we know better than that.
Edit: Just found another chart that says the 87 sport was an L4.