Line a small platter or baking sheet with parchment paper. Set aside. Wash and completely dry strawberries (residual water will prevent the melted chocolate from setting properly). Place a toothpick into the center of the green stem at the top of the strawberry, and push the toothpick 3/4 of the way through the berry toward the base.

Place chopped dark chocolate in a microwave-safe bowl. Microwave for 30 seconds on 30% power. Stir well and repeat until chocolate is completely melted and smooth. (Note: if only a few lumps remain in the melted chocolate, microwave the chocolate for only 15 seconds on 30% power).

Pick up a strawberry by the toothpick and submerge it almost to the top of the berry in the melted dark chocolate, swirling to coat well. Lift the berry out of the chocolate and allow the excess to drip off.  Set the strawberry on its side on top of the parchment paper-lined platter. Repeat with the rest of the strawberries. Place platter in the refrigerator.

Put chopped semisweet chocolate in a small microwave-safe bowl, and microwave for 30 seconds on 30% power. Stir well and repeat until smooth, decreasing the last microwave time to 15 seconds if only a few lumps remain in the melted semisweet chocolate. Pour melted chocolate into a piping bag and cut the tip of the piping bag to create a very small opening.

Remove strawberries from the refrigerator, and pipe lines of semisweet chocolate across the strawberries.

Repeat steps 4 and 5 with the white chocolate.

Allow chocolate to become firm before serving, about 30 minutes.