As I understand it, the 84 and 85 bright reds were supposed to be the same.
It changed in 86 and was not available in 87 (except for two cars that sneaked through.)
The 88 was supposed to be the same as the 86 but, for the cars I've seen, the 88 looks a little brighter.
Having said all that...
I've bought 88 red replacement parts for my 88, and the shades are noticeably different.

Several of the body panels on my 88 are slightly different shades and it's difficult to notice, even if you're looking for it.
(The front fender, above the molding, is a little darker than the door. Can't tell at all in the pics.)

[This message has been edited by Raydar (edited 10-23-2007).]