Warren,
The paragraph below is interesting from that link, as TT state on their site that they add Isinglass finings & priming sugars to the cask "the traditional way to give zest & condition". This could well be where the colour & caramel flavour comes from.
Specialty Brewing Syrup Specifications
Brewing syrups are carbohydrate blends, usually glucose and sucrose, lightly boiled to contribute flavour and condition to finished beer. These burnt sugars range in fermentability from 60% to 92%. The syrups demonstrate an increase in sweetness with increasing fermentability. They can be used as kettle adjuncts where some residual sugars contribute mouthfeel and flavour after fermentation. Alternatively, if brewing syrups are added to traditional unfiltered beer at packaging, as primings they can contribute condition (sparkle) to the finished product. In the case of pasteurized beer, the whole character of the brewing syrup passes into the finished beer to contribute palette fullness and some sweetness, depending on the adjunct used.
cheers Ross
