I think the kiln cape needs to be something like the fire cape, just a bit more amped up through states.
Maybe an HD version of lava flowing down instead of Yellow with orange polka-dots.
I like how they tried to improve it but now it goes with less of my outfits.
I do wish they gave the option to toggle things like that and choose to have them look like the older version. It's improved in some aspects and less so in other ways.
I believe it wasn't supposed to be released yet. The same thing happened with the Bandos armor getting its new looks in the current game. They aren't designed for these character models. Though we have already known that the cape would look like this from the Beta when it was out a while ago.