I would try, select the photo/shape that you want to use paint, then >effect>edges>art Stroke
Choose the 1) brush stroke (try dry brush>over mosiac or ridges), 2) select the color and 3) stroke width and transparency then 4) place the edge in front
Like in this LO:
http://www.scrapbook-bytes.com/galle...00&ppuser=4624
or
http://www.scrapbook-bytes.com/galle...00&ppuser=4624.
If the brush stroke is outside the place where you want it. Use the Marquee tool to delete the part that you don't want (select and then invert).