Hi Sunny Welcome to the Forums,
It is little bit complicated to shading the text box color when focus is on that filed. But we can it by using code.
You have to add new node(FocusFieldName) in secondary dom. You have to write the below code in OnContextChange event.
string nodeName = e.Context.nodeName;
secondaryDOM.selectSingleNode("Node Path of your focus field name", nodeName).text = nodeName;
This function executes when ever context is changed any selection or any focus is changes in the form. For every time we will set the focus field name in your ‘FocusFieldName’ node. Add condition formatting to each and every field to change the field color when focus is changed.
Condition should be like:
//Left side name of selected field and right side whichever we set the focus field name.
name(my:BriefNumber) = secondaryDOM.selectSingleNode("Node Path of your focus field name") .text;
Hope this helps you