I would suggest that you use an off white such as an ivory white as the base. Because the streaking in marble comes in many different colors, you can use browns, reddish browns and other colors. I would suggest you get a plastic sheet and practice on that first. Look on the internet for picture of marble until you find one that has the color scheme you want to use and practice painting that on the plastic sheet until you get it where you like. If you use acrylics you can paint straight on the sheet. If you use oils, then prime the sheet first with a white primer.
