Line a 9 x 9 inch pan with parchment paper (this ensure the fudge will not stick to the pan and can be peeled off easily).
Combine semisweet chocolate chips and half of the condensed milk in a large microwave-safe bowl. Microwave for 30 seconds and stir with a large spatula. Microwave for another 30 seconds and stir again. If chocolate is not yet completed melted, microwave for an additional 30 seconds. Mine took exactly 1 minute and 30 seconds total. Don't heat the entire 1 minute 30 seconds at once because you may burn your chocolate. Stir until chocolate is completely melted and fudge is smooth.
Pour chocolate fudge into the baking pan lined with parchment paper. Spread out fudge with spatula until it is evenly spread across the entire pan and the surface is smooth.
In a separate large microwave-safe bowl, combine white chocolate chips, remaining condensed milk and mint extract. Heat and stir at 30-second intervals, until chocolate is completely melted and smooth (Again, mine took 1 minute and 30 seconds total). Add in a few drops of green food coloring and mix into batter until it reaches the desired green hue you desire.
Spoon the mint fudge layer on top of semisweet layer, spreading out with spatula until it is evenly spread across the entire pan and the surface is smooth.
Refrigerate for an hour or more to set the fudge. Slice into rectangles with a sharp knife before serving.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.