Workbench "Tasks List" view renders rows with yellow background colors depending on task's priority when it's "Ready" or "InProgress". It has 2 inconsistent points:

1. Only '1' - '5' priorities are rendered.

2. '1' is the lightest yellow and '5' is the darkest yellow. It looks opposite to the priority definition in WS-HumanTask.

 
priority: This element is used to specify the priority of the task. It is an
optional element which value is an integer expression. If not present, the
priority of the task is unspecified. 0 is the highest priority, larger numbers
identify lower priorities.

Please see the attached TasksList.png

Possible solution:
Render tasks with '0' to '10' priorities. '0' is the darkest yellow and '10' is the lightest yellow. For priority larger than '10' , use the same color as '10'. I choose '10' because it is the largest value in "Task Details" priority select-box.