Wanted to make Pinkly's earrings a closer match

Hi, so I'm hoping someone with acrylic paint marker experience can help please? I recently discovered these fun treasures to customize doll stuff with lol, and I've been using them to change the colors/looks of some RH girls' accessories. I've posted pics of the green and black heels that my winter break Jade has that used to be Priscilla's coral ones, and the little accents I made on Marina's tennis shoes. And now Jewel has EXTRA teal and gold stuff - I'll post pics of those soon. So sometimes it works really well; but other times, it's a disaster. When I used glitter and metallic acrylic paint markers (Ohuhu - but I know Posca is one of the best) on the earrings Pinkly came with, it turned out splotchy and uneven, it seemed to not "take," and most of the color came off when I tried to add a top coat (Duraclear high gloss varnish).

I always first wash the items I'm going to paint with Dawn dish soap and water using a toothbrush. Should I also always use a primer like Liquitex clear gesso? Also should I finish with Mod Podge gloss instead? In the picture is what they look like originally on the left (I had bought a pair of them from AliExpress even before I had her), the results of my shoddy attempt to paint them on the right, and behind them are the two markers I used. Thanks in advance for any suggestions! 😁🌈