Painting a marble wall can seem like a daunting task, but you can do it as a DIY project. Firstly, ensure that your floors are protected with a drop cloth. Use painter tape to trim and protect the walls adjacent to your project wall. To get the marbling effect that you are after, you will need to prep three distinct colors of paint that are about three shades from one another and no more than five. If thick, thin the paint with some water. You will need a wool pad, that you should de-fuzz before using. Then wash it and blot it dry.
At this stage of the game, go ahead and apply the first color to the wall. Repeat the process for all the colors you have picked. Prime your wool pad with all the picked color choices. Use your pad to apply paint to the wall, in diagonal lines, proceeding in the same direction. Go over the area with taps of the wool pad to blend your colors and let the wall dry. For the veining effect of the marble take white paint and mix it with three parts water. To achieve the delicate effect desired use a feather dipped into the paint and gently dragged across the lip to remove excess. You will want to drag the dipped feather across the diagonal lines gently and create veiny marking by gently turning and wiggling the feather. Finally, you can use a dry brush to lighten and blur any overly overt lines. Let your beautiful new wall dry before removing the drop cloth.