Here's an interesting way to alter patterned paper to create a unique background for your digital project.
Begin by opening a colorful digital paper in Photoshop or Elements.
Press Ctrl J (Mac: Cmd J) on your keyboard to duplicate the digital paper.
Select the bottom copy and press Ctrl U (Mac: Cmd U) on the keyboard to activate the Hue/Saturation dialog box.
Move the Saturation slider all the way to the left.
Now you’ll have a color copy on top of a greyscale copy.
Select the bottom layer and click the Create a New Layer icon in the Layers panel. This places a transparent layer between the two papers.
Next, get the Gradient tool from the tool panel.
In the Options bar, choose the gradient labeled Foreground to Transparent.
Leave the other options at default values (Linear gradient, Mode: Normal, Opacity 100%)
Click and draw out a line across the page.
This will create the gradient on the middle layer.
Now hold the Alt key (Mac: Opt key) and click between the top and middle layers to create a clipping mask. This creates the illusion of the color paper fading to black and white.
To fade from black and white to color, simply switch the top and bottom layers.
Try experimenting with drawing the gradient at an angle.
You can also draw the gradient several times on the same middle layer to create a more opaque mask.