Other than colours, The shape of the jade also plays a part in determining the elemental representation of the jade. Once you know which element you are lacking, you can consider purchasing a jade that represents the element, to achieve a balanced element constitution.
Here are some examples
Fire : Triangular, trapezoid
Water : Irregular flowy shape
Wood : Rectangular
Metal : Round, oval
Earth : squarish, cuboidal
An example of how this may be useful to you when choosing jade:
If you are someone who lacks fire element but do not fancy red jade, you can instead opt to wear a triangular or trapezoid shaped jade pendant. With your element constitution balanced, your overall luck will be greatly enhanced.