The next step is putting on the color with a fairly large brush. I use a thin layer of color(oil paint mixed with turpentine) and I always use at least two hues for each object. Example: for the yellow petals I use cadmium yellow medium and yellow ochre (maybe a touch of burnt sienna where the petals come out of the center). I don’t stir the colors together, I just scoop up a little of each on my brush, dip it in the turpentine, dab it off on a paper towel so it’s not too runny and make petals using as few strokes as possible. Also, I like to work the whole canvas, not get hung up on any one part. Leaving some of the chalk marks can make it visually interesting… that’s a personal taste thing.