Shades of the method's hue, light for low parameter values and
dark for high ones. Returned named by the labels asked for, so that
scale_color_manual() is a lookup rather than a position - which is what
keeps a parameter value the same colour from one figure to the next. These
colours used to come from an unseeded sample() over a 50-colour palette,
so they differed between two runs of the same figure.
Usage
method_parameter_colors(
method,
parameter_labels,
styles = methods_style,
dict = style_methods_dict(),
labels = style_methods_labels()
)