This radar display is courtesy of the portland National Weather Service doppler radar.  Notice the bar legend on the right side of the display.  Starting at the bottom, the tan colors up through  - 0 - are indicative of ground clutter.  Light blue is very light rain, green to yellow is moderate, up through heavy rain and possible hail starting with the red colors.  Lightning is not indicated.  If you are  unsure of the display, loop the imagery for improved clarity.