Demo - Dress
To get credit, you must submit your .psd file, your exported .jpg, and your layers panel. Also, you must submit the original file, prior to editing.
To make a greyscale image, select Image, Adjustments, then Hue/Saturation or Black & White. They key is to reduce the saturation until all the color is gone.
You will use two layers to create this effect. Copy a colored image of your liking to two layers in Photoshop. Remove all saturation from the top layer to make it greyscale. Then use a mask layer on the top layer to areas of the image exposing the color image below.
