A colour scroller is an accessory which can fit onto the front of your lanterns. It enables as the name suggest to scroll or cycle through various colours of gels. These Scroller Strings as they are called) are made up of sheets of a set size and taped using scroller tape. The gel size will be determined by the scroller manufacturer. Some gel manufacturers and filter specialists may supply ready made scroller strings.
Examples of a manufacturer string – http://www.gelstrings.com
This scroller gel is then feed into the scroller unit which in turn is attached to the front of the lantern. This is accessory is then patched into the desk where the colour can then be controlled usually via DMX. Obviously this can be very useful for spaces which have limited rigging positions are a small amount of fixtures.
The accessory itself can come in various different sizes allowing application across a large number of fixtures
Matt Cooper 