AI need advise. After reading different posts about doctored red velvet cake mixes I decide to try the cake mix doctor recipe from her website (ingredients below) and instead of yellow cake mix as a base I used DH red velvet cake mix to skip using the red coloring. The cake turned out dry. Should adding an extra egg help?

These are the ingredients:

Solid vegetable oil shortening, for greasing the pans Flour, for dusting the pans 1 (18.5-ounce) package plain butter recipe golden cake mix 2 ½ tablespoons unsweetened cocoa powder 1 1/3 cups buttermilk 1 (1-ounce) bottle red food coloring 8 tablespoons (1 stick) butter, melted 3 large eggs 1 teaspoon pure vanilla extract 1 teaspoon baking soda 1 tablespoon distilled white vinegar