Look, you guys, you have to take my word on this. Titans Return Kup's colors are pretty good! He's not, like, various flavors of cyan as most photographs of him seem to claim. I swear to you, his torso, crotch, and half of his legs are this amazing vibrant teal. This amazing vibrant teal is impossible to photograph correctly, and not even Photoshop color correction can produce it. I tried. I can get close. You will look at these photographs and think, okay, whatever, that's kinda teal, but nothing to write home about. But it is. You would write home about this teal.
Unlike Sixshot (and Perceptor), Kup is not just his 1980s toy with more articulation. He's the flavor of Titans Return toys that tries to do a little something new. Mind, he still looks generally like his original robot and futuristic pickup truck in either mode, but how he gets there is a fun jaunt. For example, on the original 1986 Kup toy, you merely bent him back at the waist, tucked his arms under his hood, and generally you were done. This new version's a bit more complicated. The entire lower third of the vehicle, from front hubs to back hubs, unwraps and then rewraps to form his legs. The arms fold out of the back of the cab, which has an open drivers compartment which you have to compact in on itself for robot mode. The head, as always in Titans Return Deluxes and larger, is a little robot guy. His guns can combine into a larger gun which the head guy can ride, or it can plug into his back to replace the missing "hood" that his new transformation no longer creates.
I've talked about the teal, but beyond that, Kup's colors seem to take their cues from his original toy (and Marvel Comics appearances) rather than his appearances in animated media and subsequent comic book series. The dark gray helmet (and partially dark gray legs) are a clue to this. To me, this means this toy represents Marvel Kup, who I also call Murderkup, because he likes to murder. His earliest characterizations in the Marvel comics were that he had an insatiable battlelust. Mind, this was partly because the writer needed counterpoints to the more pacifistic Fortress Maximus to keep the desired narrative happy, but in the absence of Kup's "I'm old and I have many stories about being old!" characterization from the cartoon, his battlelust is a striking take. He just wants to kill and kill, because it's fun and he's good at it. I think this might have seeped a little into Kup's IDW appearances, where, sure, he's an old guy (and currently billions of years older than the universe itself, which is a.... long story), but he's also a member of the ultraviolent Wreckers.
Eventually painted my Kup's forearms and fists gray to more complete the Marvel Kup look. Good ol' Murderkup.
I'm just sad he doesn't get to have a cy-gar this go-round 'cuz it'd futz with his Titan Masters gimmick. Also because Hasbro would never sculpt a damned cigar into their robot toy for children. That too.