Change color of the focus indicator to match the description (#4017)

Closes [#2190](#2190)

Change the image checkbox-example5.png to make it match the description
of the failing example as suggested in [issue
2190](#2190)

Before:

![image](https://github.com/user-attachments/assets/276e56e0-7eb2-439d-b9ec-74813e22e968)
The focus indicator is #979797

After:

![image](https://github.com/user-attachments/assets/ed03d95b-13e4-4e30-a386-0398fff35533)
The focus indicator is #AAAAAA as mentioned in the description