Line a baking sheet with parchment paper or silicone mat. Pour each variety of sprinkles into individual shallow bowls.
In a medium microwave-safe bowl, pour in the dark chocolate. Microwave the chocolate in 10 second increments, stirring in between each burst, until completely melted, glossy, and smooth.
Working on one pretzel at a time, dip half of the pretzel into the melted chocolate. Gently tap the pretzel several times against the bowl to remove the excess chocolate.
Holding the dipped section over the sprinkles bowl, gently spoon the sprinkles over the melted chocolate until fully covered. Place on the prepared baking sheet and allow to set (about 1 hour). Accelerate the set time by placing in the refrigerator for 30 minutes.