This is a collection of colorized black and white images.  Special software allows the user to colorized images but it is a time consuming process.  Some pictures lend themselves to be colorized better than others.  Usually, the less complicated the image, the easier and more realistic the result.  The software does allow the user to "steal" colors from color images.  For instance, since some accident photos are in color, the colors of the track, the cars, the trees, the fences etc. can be copied and applied to the same objects in the black and white images which adds to the realism.  The colorizing has been done to lend the most realistic feel to the images without exaggeration, however this could be up to interpretation.