I have found it difficult to sharpen the color pencils (prismacolor is the only color pencil I like) using an electric pencil sharpener. I have had some success when sharpening in an electric sharpener by sharpening a graphite pencil after every second or third color pencil. In the studio right now are three damaged electric pencil sharpeners, all from color pencils.
I love working with color pencils and I store them in a silverware utensil carrier, like for picnics. One compartment houses warm colors, one for cool colors and one for neutrals. Mine has a forth, so I put a pencil sharpener, extenders, blenders, xacto, etc. I've also keep a sketchbook with high quality paper to draw on.
If anyone has any suggestions for sharpening color pencils, I would love to hear from you. Thanks, jf