Click a color button, paint away.Make sure to change the grid size and unit size before painting,changing these values mid-painting will re-create the artboard and your progress will be lost. If you want to use an image as a template, drag and drop the image onto your artboard, you should then be able to toggle it on and off.When you click generate div, a single div is created with a css block applied to it to render your artwork.Its also copied to your clipboard just in case you want to use it elsewhere.