SoulChild, I think the clear rinses can make a different yes. If you look through some of the picture galleries of the ladies on this board... you can see how much shinier their hair is.
I tried a clear rinse once... but I don't think I did it right, thus it didn't come out so well. My hair is shinier when there's a rinse in it... but since I have been coming to this board... it has been the shiniest that it has ever been (while I have been doing my hair).
The colors are temporary... depending on how often you wash and whether you use heat they will last longer or not as long.
For example... after you put a rinse in your hair... if you sit under a dryer with a plastic cap on (follow the recommendation on the back of the bottle) the color will last longer. The same is true if you put a color in when you get a relaxer. This is because the cuticle is "open" so it takes up more color.
On the other hand... if you put the color in... and the cuticle is closed... provided you don't wash it all out immediately... it won't last long at all.
HTH