Boil potatoes in pot until soft. Cut potatoes in half.
Remove insides of potatoes with spoon. Separate the inside of the blue potatoes and insides of the red potatoes in small bowls. Mash the potatoes in each bowl.
Divide the mustard, ranch dressing, and mayonnaise evenly between each bowl with each small bowl of potatoes.
Put mashed potato mixture back into the potato skins. Place blue potato mix inside red skins and place the red potato mix into blue potato skins.
Garnish with dry parsley flakes.
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.