Custom Flutter Slider

This is for a school assignment and was developed using Flutter and Dart.
3 instances of a slider Widget that I made are displayed.
The Widget is painted by a painter that I built, which extends CustomPainter.
The Widget's constructor accepts the minimum value, maximum value, number of thumbs, active color, and inactive color as parameters.
The color of the text corresponding to a thumb is changed based on whether that thumb is active or inactive.