Is it possible to set the Brush tool to paint using more than one color at the same time?
Yes, it is. The Brush tool can be set to paint different color shades in the range of the Foreground/Background colors.
1. Select two different and very contrasting colors for the Foreground and Background. 2. Click on "Brush Settings" on the Tool Options bar. 3. Raise the Hue Jitter slider to the maximum (100%). 4. Raise the Scatter slider to 50%. 5. Raise the Spacing slider to 50%.
In Elements 10 and earlier -- Click on the Additional Brush Options icon on the right end of the Tool Options bar to bring up the additional settings for the Brush tool. This icon is similar to the one for the Brush tool itself.