Well the KJ and KK headlights are different.
The way the KK headlights are tinted inside, do not affect the light output in any way.
If you were to tint the outside of the KJ headlight, it would limit the light passing through the lens.
If you were to tint the inside of the headlight, it would produce no light since the inside is the reflector creating the light output.
Here is a KK headlight.
Notice how it is just the bezel that is painted, not the lens or reflector.
Now if you were to do a real projector retrofit, that would be cool.
(I've been wanting to do this for a while, and I have done a lot of research)
Unless you mean to do something like this,
-or-
Either way Good luck!