yeah they dont change when in rider form. it feels a bit cheap but at the same time it's easier for me since it's easier to fit in the colout count. it was already kinda difficult even with the normal palette so imagine how much worse it would be if both became shiny in their rider form lol
followup, here are some corrected sprites:
corrected some details
corrected some details
corrected some details on glastrier, removed one colour from calyrex
corrected some details on spectrier, removed one colour from calyrex
corrected shiny. but it's not accurate (the horns and face on the shell are supposed to become lighter purple) because it can't fit the colour count, so i hope you guys don't mind too much. front sprite was by me and RadicalCharizard then i resized it