Chroma skin select bug

Just recently bought about 4 chroma skins, singular ones for seperate champions. I have tried some bot games with friends and wanted to try them out but there's not an option to change skin colour on the skins the chroma packs are for.

I have tried a couple games with the different champions I have them for and for none of them, chroma options show up.

Am I doing it wrong? Where do I go to change the skin to the chroma I bought? I've checked my account purchase history and they show up, and I've checked the store, and it recognises I've bought them there too.

I am not on the new client if that clarifies anything.

Thanks for hearing me out. I'll check tomorrow also to see if they're still not showing up.