There are probably few representations of Renaissance art more iconic than Michelangelo's sculpture of the Biblical hero David. In the minds of many, David clearly demonstrates the way that the Renaissance revived the subject matter and techniques of classical art after centuries of their having been forgotten.
And there's no denying that David is a masterpiece of Western art, one with far more in common with classical art than with the medieval art that immediately preceded it, thus lending support to the notion that the Renaissance was merely a continuation of the classical era after the thousand year hiccup of the Middle Ages, at least as far as art is concerned. In this popular view, artists like Michelangelo were just picking up where Phidias and Agesander left off, using the same techniques to produce works about the same subject matter their predecessors had done so long ago.
Several years ago, I remember reading some articles about art historians who'd been using modern technology, such as ultraviolet lights and high-intensity lamps, to demonstrate what classical sculpture really looked like in situ. What these historians found was confirmation of something that had been suspected for some time, namely that classical sculpture was not lily white but pigmented, sometimes garishly so (at least to contemporary eyes).
Because of these historians' work, it's now fairly common to see photographs of colored classical sculpture in many art museums. There's of course some debate about precisely how the sculpture was pigmented and whether it was indeed as bright and gaudy as some suggest, but you'll be hard pressed to find an art historian who denies that classical sculpture was painted and that such painting was a common practice throughout the Ancient World rather than an aberration.
In Michelangelo's day, no one had any idea that classical sculpture had been painted. The unearthed ancient statues used as models during the Renaissance, such as Laocoön and His Sons, were devoid of any pigment. Consequently, bare white stone was taken to be part of the classical esthetic, with some artists going so far as to provide justifications for why this esthetic was superior to the medieval practice of painting statuary. As we've learned, though, the Renaissance understanding was mistaken, based upon a misapprehension, albeit a blameless one, for there was no way that someone in the 16th century could have known otherwise.
The Renaissance esthetic, formed from a faulty understanding of classical art history, was a self-conscious one. Many artists were specifically imitating what they believed to be the classical esthetic, using the surviving ancient art that was available to them as exemplars and basing their own works on them. It didn't matter that they had often employed techniques different than those of their classical forebears or that, in addition to Greco-Roman divinities, they also sculpted people and events from Christian lore totally alien to the classical worldview. What mattered was that they were looking back on a distant past and drawing inspiration from it.
Of course, Renaissance artists, no matter how closely they hewed to the past, were not creating "Classical art," because "Classical art" is only something one can categorize after the fact. When Phidias was sculpting the statues for the Parthenon, he was not creating "Classical art." He was simply sculpting. It's only in retrospect that we can see in his techniques and subject matter things that we can later point out as defining Classical art and that later artists can then self-consciously imitate, in the process exaggerating and even ossifying our conception of what is and is not "Classical art."
There's nothing wrong with this process; indeed it's inevitable and very human. Moreover, I doubt many people would claim that David is somehow any less a masterpiece of art because Michelangelo was trying to imitate Classical sculpture in his composition. David's appeal rests not in its faithfulness to a rigid esthetic standard but because it's a remarkable work of art. That it deviates in many ways from "true" Classical art or that Michelangelo was mistaken about the ancient art that inspired him makes no difference whatsoever to one's enjoyment of what he produced -- or at least it doesn't to me.
At the same time, it's good to remember that the moment one categorizes something from the past, one is inevitably simplifying, exaggerating some of its characteristics in order to stress its genuine distinctiveness and downplaying other characteristics that evince continuity with what came before and what came afterward. As I said above, there's nothing wrong with this; it's how human beings think. We like to categorize and divide and put things in boxes marked X, Y, and Z. But, on some level, to name something, whether it be "Classical art" or "old school gaming," is to lie, because, sometimes, hindsight isn't 20/20. Sometimes we view the past through a funhouse mirror.
But you know what? I don't care.