Plasterers mix and apply different kinds of plaster to provide a finish to internal surfaces such as walls, floors and ceilings. They also mix and apply finishes to external walls using sand and cement, pebble-dash or stone-effect materials. Pebbledashing is very strong technique and maintenance free.  There are numerous coloured stones and can be mixed together.  Dashing and rendering together between rendered Tudor -look beams dashed inside, or top half of property pebbledashed and bottom half rendered are two ideas. Sand can change colour contrast.