A heartwarming video has emerged from the US of a 76-year-old grandfather's reaction to seeing colour for the first time after his relatives got him EnChroma glasses.

The footage, shot in San Antonio, TX, on February 18, shows the joyful man when he discovers colours with the help of the special glasses.

''My Father-In-Law is Red-Green Colourblind,'' the filmer later wrote online.

''When we found EnChroma, the family wanted to give him the gift of colour.''

''His reaction was priceless,'' he added.