When I moved to Michigan I was amazed by the way the leaves turned colors. I thought it was the coolest thing ever. It took me a while to figure out that this was because they were dying. In Florida, the leaves don’t change colors the way they do here. In order to create this effect:
I first found a tutorial.
I duplicated the original layer and then hid it.
I went to Image > Adjustments > Black and White
I used the lasso tool to outline the leaf I wanted in color.
I then erased inside the lines and made the original layer visible.