Apply Style to Table Cell Text using Extendscript CC

Hello,

I have the following code. I'm attempting to parse a document and search for specific keywords based on regex. This part is working. I then get the text range for those keywords and highlight the text. This works. What doesn't work is when I try to do the same thing in text that is in a Table Cell.

#target framemaker
var doc = app.ActiveDoc;
var totalPgfs = 0;
var pgf = doc.MainFlowInDoc.FirstTextFrameInFlow.FirstPgf;
function do_table_work(pgf){
    var result = pgf.GetText(Constants.FTI_TblAnchor);
    var all_text = '';
    for (var i = 0; i < result.length; i += 1) {
        var t_object = result.obj;
        var t_cell = t_object.FirstRowInTbl.FirstCellInRow;
        while(t_cell.ObjectValid()){
            var cell_items = t_cell.GetText(Constants.FTI_String);
            var tr = new TextRange();
             tr.beg.obj = tr.end.obj = pgf;
             tr.beg.offset = 0; //this is built dynamically
             tr.end.offset = 7; //this is built dynamically
            apply_char_format(text_range)
            t_cell = t_cell.NextCellInTbl;
        }
    }
}
function apply_char_format(text_range, name) {
    var color = doc.GetNamedColor(name);
    if (color.ObjectValid()) {
        var set_val = new TypedVal();
        set_val.valType = Constants.FT_Integer;
        set_val.ival = true;
        doc.SetTextVal(text_range, Constants.FP_UseBkColor, set_val);
        set_val.valType = Constants.FT_Id;
        set_val.obj = color;
        doc.SetTextVal(text_range, Constants.FP_BkColor, set_val);
    } else {
        alert('Color does not exist');
    }
}
while (pgf.ObjectValid()) {
    do_table_work(pgf);
    pgf = pgf.NextPgfInFlow;
}

The problem is it's not highlighting the text in the table cell like I want it to. If I process the document, and use the following:

var result = pgf.GetText(Constants.FTI_String);

It will highlight the text (with additional code to loop through those results).

Any thoughts on what I'm missing?