There are many ways to recolor an image or part of an image with Photoshop and in this tutorial I will show two ways to work with a file to accomplish this task.
The first method is using Adjustment Layers, and the second is using regular Image Adjustments. Each one has its advantages and disadvantages so it becomes your choice.
Start with the garment document you want to recolor and make a selection around the entire garment to be recolored. I used the Quick Selection Tool here but you can also use the Magic Wand, Lasso Tools, Pen Tool or even Color Range under the Select Menu.
Its also nice to be able to go back to our selection later on without having to reselect it, so go to SELECT>SAVE SELECTION, give it a name and hit OK.