How to make Gantt bar color dependent on condition: if a task is a child (subtask) of a selected par

I have created a sheet based off of the Team Task List by Priority template.

I have changed the priority task names to reflect the names of our team members. This allows me to group the tasks by tech, so the sheet's description would more accurately be Team Task List by Tech.

I had conditional formatting set up to color-code the Gantt bars so each tech has their own color. I had to make it conditional on the Assigned To column.

The intent was that users would drag and drop the tasks from one parent task (by tech) to another tech's parent task when they wanted to reassign the task to another tech. However, the techs, in practice, are finding it easier to simply chang the tech in the Assigned To column and not move the task.

I want to eliminate the Assigned To column so that techs will be forced to move the task to a different row to reassign them. However, the automatic color coding of the Gantt bars depends on the Assigned To column, so I lose the nice color coding of the Gantt bars by tech.

I would also prefer to simply change the task assignment by choosing the tech's name from the column, as the techs are currently doing, but that defeats the purpose of having the sheet organized by tech grouping.

Is there a way to make the color coding of Gantt bars dependent on row location OR parent/child task relationship? Or am I only able to choose columns?