Yes, the suggestion that they're trolling goes too far.

However, I did a tiny bit of investigating, and according to this write-up it does seem like Brinkmann presents his work as resembling the originals

https://www.smithsonianmag.com/arts-culture/true-colors-1788...

But they still don't add anything without direct evidence - where there's evidence in later statues for more subtle colouring, they include that.