Toner, dye, and washing...

I've got yellow hair extensions that I toned purple, now they're kind of mix of grey, purple and a bit of yellow. I will try and put turquoise onto them now. I toned them as I want blue turquoise, nothing green-like, seafoam-y, just pure blue-based, bright turquoise, and the thing is, I was wondering... when I wash my hair or the hair extensions, will the toner that's underneath the dye wash away? I don't want to suddenly end up with green hair, but then again, how do I tone my hair if the dye is on top of it? Do you know what I mean?

and last question, after I keep the dye for however long I will keep it, do I just rinse it or do I need to wash my hair/hair extensions?

Thanks so much!