Score colour constants
score_colors.RdBreakpoints and colour vectors for DT table styling and ggplot2 plot
colouring. Below-threshold uses soft green; outlier bands graduate from
yellow to red. SCORE_COLORS_TABLE uses white for the first band and
yellow-to-red for outliers. SCORE_COLORS_TABLE_TEXT provides foreground
colours for DT cells. Query dots use light purple (no change) and blue
(data change). These can be overridden at runtime via apply_config().