Green is a cool, soothing color within the auric spectrum. It corresponds to the element of earth and to the Heart Chakra.
Keywords to describe a blue aura person would be: friendly, healing, positive, sociable, spiritual, stubborn, tenacious, natural, connected, communicative.
A more in-depth analysis of what a green aura means can be found in my previous entry here. Many shades of green are listed, so you can find your specific shade meaning easily. :)