Why did my gold delivery Pokemon turn into rainbows?

Question

I play Cafe Remix and lately, if I get several gold Pokemon in a delivery, they show up on screen then turn into a rainbow Pokemon package instead. I’m not complaining, as it’s finally giving me some I don’t have maxed. (All of my gold Poke are capped out on their mug levels) I just didn’t understand why it’s happening now?

Comments

I also am not sure that this matters, but it did it first with Mawile. Capped her out, now it seems to be focused on Fuecoco.