Saying the following although what you had declaimed was already solved: 
 Acutally the black smiley had not been that much of a bad idea, since it shows, that the red color of it is  n o t  of importance to the sign, it may contain. Why I do think that to be a fact, because he arranged a white face out of fog be drawn in the sky in episode 23 of season one? )  Although of course, he didn't run the usual procedure there, I do think, that this explains, that the color does not acutally effect the conclusion of the Red John-Smiley.