I'm collecting late medieval and early renaissance artwork for a personal online project.
In doing that, I've accumulated a number of early-internet black and white images which I know originally come from full-color paintings -- because I've seen some of those paintings in the past.
Neither Google Images nor Tineye seem to be able to find color versions of b&w images, nor are text-based searches including the artist's name or work's name (in those few cases I know either) working.
I'd really appreciate any suggestions as to how to use the b&w versions I have to find the color originals!
An example? Here's one. I've seen this online in the form of a subtly-textured but wildly colorful painting dozens of times in the past, but can't use this sketch version to find that again. Same with the others.
The sketch itself is attributed to Heinrich Aldegrever, and titled 'Bildnis eines Jungen Mannes':