Paint underneath stones?

https://priveporter.com/products/hermes-25cm-birkin-customized-rainbow-chevron-swarovski-crystal-palladium-hardware-hermes

I have never rhinestoned in my life but I’m trying to recreate this purse and I got 2 months to do - but it kinda looks like it was painted under before rhinestoning? Or does that just look like that when you rhinestone? Can anyone else confirm? I assume 4 mm could work here ?

https://priveporter.com/products/hermes-25cm-birkin-customized-rainbow-chevron-swarovski-crystal-palladium-hardware-hermes

I have never rhinestoned in my life but I’m trying to recreate this purse and I got 2 months to do - but it kinda looks like it was painted under before rhinestoning? Or does that just look like that when you rhinestone? Can anyone else confirm? I assume 4 mm could work here ?