When supping your ale
What colour should it be?
Joseph W. Lovibond invented the tintometer, a visual colorimeter, and a system for colorimetry based on subtractive color mixing.
Evolution of the Method.
The writer was formerly a brewer, and this work had its origin in an observation that the finest flavour in beer was always associated with a colour technically called "golden amber," and that, as the flavour deteriorated, so the color assumed a reddish hue. It was these variations in tint that suggested the idea of colour standards as a reliable means of reference.