It is not that difficult .. At time of loading the CLV you can set the Background / Text Color properties of the Label / EditText for a single Item/Row
depending on a certain condition.
Or .. maybe on Row click access the row item panel / views to change the properties.
The following uses a Button click as found in the xCustomListView example
Here ....
Sub Button1_Click
Dim index As Int = clv2.GetItemFromView(Sender)
Dim pnl As B4XView = clv2.GetPanel(index)
Dim lbl As B4XView = pnl.GetView(0) 'the first view within panel
lbl.Color = Colors.Blue
lbl.TextColor = Colors.Yellow
End Sub