Gantt chart - Distinguish consequtive events

This is a 2 part question.

I have the following chart where unit 2 and 3 have multiple consequtive tasks using the same resource.
So when i used the following arguement (index_col=‘Resource’) so that they are grouped as such, the entire block turns into a single colour and it is not possible to distinguish each of these consequtive tasks. Is there any way to do that? One idea i had was to have an outline around each box/task.