I am not sure I'm understanding the issue BUT I was able to individually format shaded areas.
1. Select the area to be shaded
2. Right-click, select format
3. In the format pane, change the shading to the desired color
4. repeat for the desired shaded areas.
Heat map chart - Revised.twbx 102.3 KB
Wow. You made it seem so simple. Thank you so much for the help issue is solved. Appreciate it.