[Al Skierkiewicz]

Topper,
Are you using a fabric cover to make your bumper one color? Maybe. If you are asking can you use velcro to secure the bumper to the robot, then the answer is No. The bumper system must be attached in such a way that it can take a hard hit from another robot or part of the field and not fall off. The figures included in the rules give you a good idea how bumpers should be put together and what they should look like.
Welcome to robotics by the way.