secondaryActiveColor property
The color to use for the portion of the slider track between the thumb and
the Slider.secondaryTrackValue.
Defaults to the SliderThemeData.secondaryActiveTrackColor of the current
SliderTheme.
If that is also null, defaults to ColorScheme.primary with an
opacity of 0.54.
Using a SliderTheme gives much more fine-grained control over the
appearance of various components of the slider.
Ignored if this slider is created with Slider.adaptive.
Implementation
final Color? secondaryActiveColor;