withoutHues method
This steering without its hues (colours and hue range), keeping the
brightness and chroma they imply.
With tonal, the harmony stays tonal while the intent sets none.
Implementation
Steering withoutHues({bool tonal = false}) => Steering(
ThemeIntent(
brightness: brightness,
chroma: chroma,
harmony: intent.harmony,
name: intent.name,
),
centred: centred,
tonal: tonal,
);