The Wikipedia article on Ancient Greek Sculpture tells a little of the story. Paint flakes had often been found on the statues but had been ignored, even denied. It wasn't until modern technology and the work of Vinzenz Brinkmann and Ulrike Koch-Brinkmann that the light (and colour) dawned upon the scene.
This 2014 piece tells a little of the story. This 2016 piece on a current exhibition a little more.
I have to say that the colours are a little garish by current tastes. This one makes the lion look a little like a stuffed toy sitting on a child's bed!
Still, it is nice to know that there was colour around. Some of those Greek homes and temples would actually have been very drab without it.
Another reminder too about the difficulty of actually knowing the real texture of the past. As an example, it wasn't until my visit to the Greek Isles that I realised just how important water was to settlement. I did know how important trade was, but it didn't form a real pattern in my mind until the visit.
The same sort of thing applies to Australian history. When I first studied Australian history, the near starvation of the early settlement at Port Jackson was attributed to poor farming techniques. That may have been a factor, but we also now know that there was an El Nino induced drought.
I should leave the last word on Greek statues to a comment from JCW at another place:
Funny, innit; whole literary/dramatic theories have been written about the differences between Apollonian (cool/white/ classical/contained) and Dionysian (unrestrained/colourful/extreme), based on modern(ish) observation of classical statues, wot were never white in the first place. I bet Apollo and Dionysus are laughing their silly heads off after getting pissed on nectar, and agreeing that humans are pretty stupid for getting it SOOOOO wrong.