Describe the product and scratches? Share photos maybe?
Such products only work when the paint layer isn't completely off. If you see the bare metal beneath, the best idea is to get an enamel with the exact color, it's not easy because the color will change once the paint dries.
IMO, your options are:
1. Nail paint
2. Enamel paint
3. Acrylic colors
Ideally, you should be able to experiment on a spare piece of metal and try to get the exact color before actually fixing the scratch. Mix and match different acrylic colors or nail paint.