I just saw the front page post about automatically colorizing photos (<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10864801" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10864801</a>) and thought I should share this website I built a couple years ago. It allows grabbing color from a reference photo and painting it onto the black and white image you wish to color.  It was a fun learning experience and can make some pretty convincing photos with a bit of patience.