Green indicates the air going toward the radar, and red is away. When you see the bright red, right next to the bright green, that's called a couplet, and indicates strong rotation within the storm. You can see this in the image below just west of downtown Paoli.
Sometimes that rotation can hang above the ground and not produce a tornado. Either way, strong winds dropped from this storm and caused damage around the Paoli area last night.
Below is the radar reflectivity. Right where you see the rotation above, west of Paoli, you can see a bit of notch or curl. This also indicate rotation. With strong rotation you often get rain wrapping around the circulation, an indication a tornado could be present. We'll let you know what the National Weather Service finds from this location later today. Stay tuned!