photoshop workshop- black and white with colour

to create a black and white image. with aspects of colour. first copy the background layer.
then with the copied background. turn it black and white . (using image, adjustments and black and white)

next select the erase tool, and change the size. now erase parts of the picture that you wish to be in colour. this will allow the bottom layer to be seem so it seems that the image has colour.