Ombre fabrics are magical because you can use many different shades that blend seamlessly together.
Ombré ("shaded" in French) is the blending of one color hue to another, usually fades from light to dark over a length of the fabric.
The color in an ombre fabric is all the same hue, with shades and tints added. So, for example, if the color fades lighter, then they add white and black to the original fabric hue if the color fades darker.