You can remove the green stain on metal by treating the rust stains with a cleaning agent such as a lime remover or some kind of harsh acidic substance.
If you are using a carpet cleaner, Rug Doctor offers a green cleaning solution. It is available at Sears. For spot cleaning and stain removal, rubbing alcohol can be used. Simply soak the spot in alcohol, blot it in with a rag, and once it dries the stain will disappear.
Some cleaning products you can use to shampoo a green carpet include Hot Water Steam Cleaning, Stomp 'n Go and Oxy Carpet stain remover. You can purchase these items online from the Amazon website.
try cleaning it
malachite green stain
Where the stain is you put baking powder over it or rub stain with carpet cleaning
There is a great website that features many stain removal recipes for carpet cleaning with different solutions broken down to the actual item that caused the stain. The website can be found at the following URL address: http://www.carpet-cleaning-tips.com/cleaning-carpet-stain.html.