Overlapping tasks in discontinuous gantt chart

There must have been a change because @WolVes solution didn’t seem to work for me. For anyone that happens across this, I was however able to set transparency using a similar method:

fig = ff.create_gantt(data, colors=colors, index_col='Resource', group_tasks=True, showgrid_x = True, showgrid_y=True)
for shape in fig['data']:
    shape['opacity'] = 0.25
fig.show()

Or, individually like:
fig['data'][2]['opacity']=.25