Little Greene Paint Smalt (255)Little Greene Paint Smalt (255) Smalt No 255. LRV (Light Reflectance Value) The origins of smalt as a pigment and the encapsulation of cobalt into glass, dates from as far back as 200BC. This technique resurfaced and rose to the height of popularity in the 18th century. If you are unsure of colour please purchase a sample pot. We highly recommend testing a paint colour before purchase. Sample pots are available in every colour and come in an absolute