Both the color and black-and-white images are from the same negatives, but the B&W one uses only the red information and was processed differently in Adobe Photoshop. For the color image, the most disagreeable aspect is the brightening in the center, which is due to the inevitable partial vignetting of the photograph. In a normal picture this would be invisible, but in a contrast-enhanced photograph it becomes obvious. The vignetting is less apparent in the B&W image because it was removed by application of a radial gradient mask; however, this method (in my hands) always leads to ugly color artifacts when I use it for color photos.
A satellite passed through the field during one of the exposures, and its faint trail is visible running nearly vertically down the center.