What Xresources reference will control tk_chooseDirectory background? Non-responsive to specifications

Question

I have tried many different .Xresources definitions to control the background colour for the box which displays directories and files in the tk_chooseDirectory widget, without success.

I was hoping to locate the source code for tk_chooseDirectory, hoping that would reveal the name of the controlling resource, but I have not been able to locate that.

The context of the widget call is as follows:

proc tkecl:getDirectory {initdir title} {
    return [tkecl:get_path_popup $initdir directory \
        [list tk_chooseDirectory -initialdir $initdir -title $title]]
}

tk_chooseDirectory itself does not allow specifying such colour control at time of call, so how can I override?

Based on suggestions, I confirmed the foreground colour is controlled by:

*Canvas.foreground:     #008F00

That should imply background is controlled by

*Canvas.background:     #1F1F1F

However, tk_chooseDirectory ignores that resource definition. On a lark, I tried

*Canvas.fill:   #1F1F1F

but that did not have any impact either.

How do we get around that ?

I even tried variations involving

!Xt*.background:        #000000
!Xt*.foreground:        #FFFF00

!Xaw*.background:       #000000
!Xaw*.foreground:       #FFFF00

!Xm*.background:        #000000
!Xm*.foreground:        #FFFF00

!Xraw*.background:      #000000
!Xraw*.foreground:      #FFFF00

Is there a central file that controls the look and feel for the class of widgets to which tk_chooseDirectory belongs? If so, where is that?

The developer of the application has been unable to identify the resource that controls the background for tk_chooseDirectory.

tk_chooseDirectory even ignores statements of the following form coded immediately before the call:

option add *Canvas.background       "#1F1F1F"   userDefault

or

option add *Canvas.background       "#1F1F1F"   interactive

What gives???