To modify the representation of a label you must know which label goes with which control. It isn't always so easy to know that, depending on the way the control was created. However, if you want to disable a control, make yourself a subroutine for which you supply three arguments: two controls and a yes/no field.
Inside the subroutine (which should be a Public Sub in a general module), you can look at the Yes/No field and the two controls. If either control is a label, you can set the ForeColor or change the BackColor or both. You have to look at the .Type property of the control to know that it is a label control. If the other control isn't a label, it will likely have a .Enabled property and a .Visible property, both of which can be set or cleared in your routine.
Once you have this subroutine, you can choose to call it from event code underlying your form. I did this once or twice. In my case, I just made a sequence of calls to enable or disable textboxes, to be run every time certain fields got changed. I passed in the names of the control and its associated label and my state selector.