Well, the US might not air till Sunday but Canada aired the episode Thursday night and I was not disappointed. It's titled "Nothing But Blue Skies" but they went out of their way to over-include the color red when filming and at the very beginning of the episode the music seemed reminiscent of the RJ drum beat. I'm not saying the RJ is likely to come back because the whole episode was full of call backs to classic episodes but this episode would set it up nicely if that were the case.
The titles of the episodes this season go through the entire color pallet except the color red and what do you know but the season finale is the only episode that's been left untitled.
In previous theories, I've theorized that RJ's secondary colors are orange and yellow. Orange is the tiger's color and the color of fire/explosions. Yellow is the color of the flowers RJ left Jane after killing Bosco. (Jane's colors are blues and Lisbon's are green). Episode 3 is orange, episodes 4 and 7 are yellow, episode 11 is purple which is a mix of blue and red, 12 is brown which could be dried blood, and 13 could be red. If I were to insert a hunt for RJ into the titles this is how it would look:
7x01: "Nothing But Blue Skies" -everything seems fine but remember the RJ smiley in the sky
7x02: "The Graybar Hotel" -gray prison bars = stripes = tiger
7x03: "Orange Blossom Ice Cream" -orange for tiger tiger or RJ
7x04: "A Hint of Yellow" -a hint of RJ
7x05: "The Silver Briefcase" -silver is the color of Mashburn's car
7x06: "Green Light" -Lisbon and the audience come on board to Jane's plan
7x07: "Little Yellow House" -RJ's house
7x08: "The Whites of His Eyes" -Jane gets too close and RJ finds out at end of episode
7x09: "Copper Bullet" - RJ's move and Jane realizes RJ is on to him at end
7x10: "Nothing Gold Can Stay" -everything goes to hell
7x11: "Byzantium" -long awaited meeting of RJ and Jane, mix blue and red
7x12: "Brown Shag Carpet" -dried blood - Vanpelt and Rigsby murdered, the child lives
7x13 ? -Jane catches RJ, Jane & Lisbon raise the child
And yes, I'm stilling theorizing under the idea that RJ is Walter Mashburn. We saw him shake hands with Jane, has a mild dirt phobia, his episodes are full of the color red, is the only suspect that even comes close to having a similar personality to Jane's, lost his wife to Yuri, childhood issues that resulted in reform school, extensive experience with explosions, continually baits Jane, has the funds to be RJ, has talked to Jane about Jane's issues, only suspect that was carefully developed into a three-dimensional character, one of his episodes was written by Jordan Harper who is writing episodes 2, 5, and 11 - which are the two episodes with silver/gray and byzantium which is closest to red.
If I'm right, then RJ tried to use Jane to expose the tiger tiger group in the S2 finale with the words "tiger, tiger." S3 was Jane accidentally antagonizing the tiger tiger group in his search for RJ and RJ deciding to give Jane closure because he wanted to get to know him as Mashburn or because he was insulted by the mess Jane made with tiger tiger. S4 was Jane reaching out to RJ with an offer of friendship and then RJ getting pissed when it was a con. S5 was Lorelei's and it brought the game to dangerous levels with tiger tiger and Jane knowing he'd met RJ and making the list in the notebook of his suspects and RJ countering by sending Jane a list of tiger tiger suspects. S6 Jane takes out tiger tiger and fakes the explosion and deaths of the people in the house. Jane made a plan with McAllister, Stiles, and Haffner(Stile's Visualize puppy inside law enforcement) to take out tiger tiger and to throw RJ off track. McAllister and Stiles will return to help Jane. McAllister will give the names of all the tiger tiger members and Stiles will return to his cult.
One last stupid theory to hope for . . . but the season looks promising regardless of any ludicrous theories I might write out.