Line an 8x8 pan with parchment, letting it overhang for easy lifting.
Melt white chocolate and condensed milk slowly on low heat until smooth and glossy.
Stir in peppermint extract, salt, and green coloring to evenly flavor and tint the fudge.
Fold in chopped Oreos, saving some for topping.
Spread the mixture in the pan and sprinkle the reserved Oreo crumbs on top.
Chill for 2 to 3 hours until the fudge becomes firm.
Lift, slice, and serve clean squares using the parchment overhang.