Ah, as I rather like IC70 seats, I would have probably have preferred that regardless of upholstery !
I used to until last weekends trip on the Night Riviera, don't get me wrong the service is fantastic, but those IC70s I'm afraid to say have had their day - the recliners just about work but some can be rather tempremental and recline on their own in the middle of the night, the springs are becoming very noticeable underneath and those fixed armrests make the seat very uncomfortable. They were great, but having had the pleasure of a FGW HST the next day I preferred the Primarus ones in those. But I guess it's all about tastes really, and having said that if I can get hold of one one day to 'upcycle' and remoqutte.
As for the 70s colours, as a avid Air Cooled Volkswagen owner and fan, I'm quite used to the rather funky range of 70s colours - The Bright Oranges, Greens and Browns don't faze me anymore
Another one for awful interiors would be the dreariness of Wessex Trains fleet - I've mentioned how bad the 153s were earlier, with the 158s in the same state both internally and externally (although for irony the 153s had 158 Seats and the 158s had 153 seats), The 150s were refurbished in everything Grey with the only tone of colour coming from the pink grab handles at the top of the seats, which were upholstered in Grey with Maroon flecks. An interior which almost makes Northern Rail's refurbishments sound positively exciting, which given what FGW has shown to improve their 153s isn't as good as FGWs!