IMG_0509.JPGDepends how light your talking, pics would be handy. However I believe that it could be a nitrogen deficiency, although again, without pics its hard to tell. Just re-read your post though you said the new leaves are light green, which I think is pretty normal, most new growth tends to be a lighter color than established leaves and obviously some plants are lighter in color than others. As long as they are not starting to turn yellow in color I think you´ll be ok.
Oh ok well I have never seen it and there about 2 inches long the leavesnewly sprouting leaves are always a lime green color