Yes, on our bikes, the decals are applied over the paint and can be easily changed. For example, this allows the design of an older bike to be updated to match that of the current models.

The decals are best removed by warming them slightly with a hairdryer first. Then, they can be simply peeled off. Before applying the new decals, the frame should be cleaned with some brake cleaner or spirit to ensure it is free from dirt and grease.