Like all effects: For some wishes, it's ideal, for some others, it's not.
Your output could have been (slightly) better if you've chosen a darker output color.
But I admit, your example, the large color span to replace (from almost white to a darkgreen), doesn't seem to be the ideal challenge for this effect :wink:
On the other hand, this effect goes further/faster than lots of other color replacing effects I've seen so far. Like I said, it depends on what/how you use it, I guess.
It can also be used to remove parts of an image, (un)like 'magic wand' + 'delete'.