Customise hover line path of parcats plotly.js chart

I’ve used a plotly.js parcats chart to make a sequential sankey (eg GitHub - EE2dev/sequence-explorer: Exploring sequential data with a sankey diagram). Here is the example parcats which shows changes in grades between quizzes:

var trace1 = {
  type: 'parcats',
  hoveron: 'color',
  dimensions: [
    {label: 'Quiz 1',
     values: ['Black', 'Black', 'Black', 'Brown',
              'Brown', 'Brown', 'Red', 'Brown']},
    {label: 'Quiz 2',
     values: ['Brown', 'Brown', 'Brown', 'Brown',
              'Brown', 'Blue', 'Blue', 'Blue']},
    {label: 'Quiz 3',
     values: ['Female', 'Female', 'Female', 'Male',
              'Female', 'Male', 'Male', 'Male']}]

var data = [ trace1 ];

var layout = {width: 600};

Plotly.newPlot('myDiv', data, layout);

When I hover over a path the full path from ‘Quiz 1’ to ‘Quiz 3’ highlights but what i’d like is for only the path between ‘Quiz 1’ to ‘Quiz 2’ to highlight. I tried hoveron but nothing changed.

Is there a way to customize the hover functionality?