Help painting will o wisp spheres

[zombiepaints]

What is the best course of action when painting basically a ball of light. My first instinct is to paint it as a precious gem and then using lighting effects on the tree next to it to get the effect that its is the light source.
is there a better way of doing the spheres? any suggestions are welcomed!

 

[QuietiManes]

Short of fitting it with LEDs, that sounds about right. Maybe a small white dot in the upper half and fade out to yellow for the majority of the sphere.