Colour preference, naturalness, vividness and colour quality metrics, Part 2: Experiments in a viewing booth and analysis of the combined dataset

In Part 2 of this work, observers scaled colour preference, naturalness and vividness visually on interval scales (0–100) labelled by semantic categories (e.g. ‘moderate’, ‘good’ and ‘very good’) in the context of food lighting using the same questionnaire as in Part 1. Seven multi-LED light sources with more or less object saturation effect illuminated a viewing booth with coloured food objects. The two datasets (Part 1: room + Part 2: viewing booth) were merged and the observers’ assessments were predicted by recent colour quality indices and CIELAB chroma differences. Linear combinations of selected pairs or triads of descriptors were used to predict the merged dataset. Criterion values to achieve ‘good’ preference, naturalness and vividness level were determined.