I'm not sure if I'm using this wrong or if it's a bug, but hitting "next" takes me to to leather and metal dye, as well as progressing the colour palette. I'm assuming that it's only supposed to progress the colour palette.
I experimented several times with this, the bug doesn't always happen. I'm not sure what triggers it. Also, when I click on a colour and go to select a colour slot, it switches the option to leather or metal.
Another thing that might be useful to include is an option to select a specific colour.
Edit:
After a bit of experimentation, it looks no matter what the text says, it actually is targeting the correct piece to dye.