Some examples.
The white marbled Greek statues are not meant to be austere colourless figures. The paint plastered on them has fallen off. If you ever actually saw a Greek sculpture with the paint still on it, it looks as loudly coloured as an Hindu idol.
The first settlers in the United States didn’t dress fancily with pointed hats and dark clothing, even when farming or constructing. What paintings assumed them to look like is based on British Pilgrims who stayed back home, not actual inhabitants of the New World.
The Vikings never wore horned helmets, nor were giant muscular men. That was just exaggeration, recounted by terrified Roman men.
Ancient people of India didn’t look one bit like how TV serials or paintings on the Mahabharat or the Ramayana depict them to be. Many of the supposed events that happened then had happened a few millenia back. A few centuries after they happened, some scholar wrote down what was passed down to him from memory and oral tradition. Then another millenia later, most of these writings were destroyed, with few copies still lasting in readable condition, picked up by medieval kings in the eastern part of the subcontinent. They translated them into the languages of the day, making assumptions on meaning of phrases, and the painters depicted clothing based on what medieval people of the day looked like and not what the original people of those times actually did.
But even those translated copies were lost or destroyed, with a few still remaining. When the Indian nationalist movement started in the colonial era, India was just a geographic region, and its loose inhabitants were in search of a common past or a culture. If they didn’t have any, it was necessary to invent one. Taking some of those scriptures, they attempted a rennaissance based on a whole new interpretation, and filling in the gaps as they saw fit. Thus, newspapers like Kesari and journalists like B. G. Tilak “revived” festivals that may never have existed before in India, like the sinking of Ganesh statues in the Bombay sea and Dusshera. In short, much of what is now called “Hindu culture” is actually an invention of 200 years ago, based on pure assumption and casuitry.