Navigation:  Composition > Adjusting Backdrop Colors

This backdrop precedent over everything else on the scene can be easily observed by changing the backdrop colors.

Those adjustments are in the Composition ->Adjust Backdrop Colors menu. Same settings and so I simply adjusted the gamma of the backdrop.

 

 

By adjusting the backdrop darker Photo Blend also darkened the objects accordingly as to be part of the scene and didn't have a problem with it.