Your code does work for WdGreen! The problem is your green font isn't actually the vba WdGreen,
although Word sets it as green. The vba green & the Word green have the same value (11) but are different colors!
Check for yourself using RGB codes: the genuine (vba) WdGreen is R=0, G=128, B=0 but your Word green is anything else.
It's strange, but the Word's Find-Replace dialogue recognizes the Word's green, set using the Find-Replace Format Font dialogue,
but doesn't recognize the vba WdGreen, while the vba / macro code recognizes the vba WdGreen but is blind to the Word Green.


To make the macro work for your "green", select any part of the colored text & use
msgbox selection.Font.ColorIndex
to get the code of your color. Then replace WdGreen in Find with the obtained code.