setScheme method
Implementation
void setScheme(Color customPrimary) {
primary = customPrimary;
primary50 = Color.lerp(primary, const Color(0xffffffff), 0.15)!; // 较浅的颜色
primary100 = Color.lerp(primary, const Color(0xffffffff), 0.4)!; // 更浅的颜色
primary200 = Color.lerp(primary, const Color(0xffffffff), 0.65)!; // 最浅的颜色
primary300 = Color.lerp(primary, const Color(0xffffffff), 0.85)!; // 最浅的颜色
primary300Opacity = primary300.withOpacity(0.4);
}