The colors in the Resources tab are based on the Projects and not on Task Assignments.

If you have created only one Project and assigned Tasks for that specific project, you see all the Task Assignments with the same color in the background in the Resources tab.

If there are multiple Projects with multiple Task assignments to users, then they show in different colors in the background as in the screenshot below.

  • e.g: All the Task Assignments marked in Red belong to one Project, and the Task Assignments marked in blue belong to another Project.