These are the colors of beers of "average spectral characteristics" viewed in a glass of the indicated thickness with Illuminant C. "Average" is based on an ensemble of 99 beers including some lambics and framboises which render the average slightly redder than "normal" beers. Relative to this average normal beers have a first SDC of around -0.5 (for comparisons krieks have a first SDC of nearly +2).