Now comes the fun part--aw heck, it's all fun, right? Anyway it's time to colorize the stars as you described them in your sketch or notes. Grab a soft paint brush that is slightly larger than the star, set the paint brush to "color" mode, and give it an opacity of 20% or so (see Figure 11). Next, whip up the color you want to apply to the star. I've found that I like to set up a swatch palette of the most frequently used colors that I can just pick from when I need it (see Figure 12). With the color ready, move the brush over the star and click one or more times to dab the color on. More clicks will give you stronger color (see Figures 13 through 15). Lower the opacity on the brush further if you need to get a very subtle color. Since the paint brush is in 'Color' mode, it won't brighten or darken anything. It will just colorize the existing values.