Black and white labels are distinct, and a great way to visually differentiate information which is separate to your colour code system. For example, you may use colour coded alphabet labels for client initials on the spines of your files, but you may also wish to add a client ID number. Having both of these pieces of information colour coded could be confusing, so you may wish to use black and white labels for this ID number.
Sheet of 20 labels. Black and White. Half Size. Numeric.