When using the DisplayName property, whether in E-Basic script or as an attribut reference, the BackColor property of an object may not appear as expected. This is caused by an internal flaw in this particular build of E-Prime.
The only way to fix this is to edit the DisplayName and BackColor property direct in the Display Device. You can find this by double clicking on the Experiment object at the top of E-Studio's Structure window, clicking on Devices and double clicking on the Display device. Please make sure that all values in this dialog are hard-coded (i.e. no attribute references).
Update to E-Prime 18.104.22.168 or later.
This item corrected in E-Prime 22.214.171.124