I’ve heard (and Greg has stated many times) that the way BIONICLE sets and characters are created is that the design team creates the actual toys first, and then Greg somehow adds the story and characterization to them.
And the fact that Kongu Inika has silver has nothing to do with the fact that Greg explicitly said “No, Nidhiki hadn’t silver”.
In addition, Kongu Inika is a special shape-shifting being, while Nidhiki is a normal Toa.
For me personally, the silver and green Nidhiki are very good too.
But I would like to support the Full green Nidhiki because I want to respect Greg’s statement as much as possible.