Changing foreground and background color in GtkListView rows

[marcodev comcast net]

I have the following code creating the column and its renderer in the list:
{
......
     vars_list = gtk_tree_view_new ();
     renderer = gtk_cell_renderer_text_new();
     column = gtk_tree_view_column_new_with_attributes(var_list_col_title,
                                                       renderer,
                                                       "text", 0,
                                                       NULL);
     gtk_tree_view_append_column(GTK_TREE_VIEW(vars_list), column);
......
}

The list displays the values of variables in memory and is updated by a timout that runs periodically. When a 
variable is added (appended) to the list I use the following:

void
APPEND_TO_CLIST(GtkListStore *LIST, int ROW, char *STRING)
{
.....
   GtkTreeIter iter;

   gtk_list_store_append(LIST, &iter);
   gtk_list_store_set(LIST, &iter,
                      0, STRING,
                      -1);

   if(ROW % 2 == 0)
   {
      g_object_set(renderer, "background-gdk",
                                  MM_GLBL->COLORS.CLIST_BG_A, NULL);
   }
   else
   {
      g_object_set(renderer, "background-gdk",
                                  MM_GLBL->COLORS.CLIST_BG_B, NULL);
   }
....
}

The above however is not changing the color on the background as I expected it. Am I even doing this right?

The following issue might be related to the same problem I have with the code above, when the value of a 
variable in the list is updated the value should be displayed in one color (black) and when the value has 
remained unchanged for a period of time then it should switch to another color (red). This is the code I use 
for this:

void
UPDATE_CLIST_VALUE(GtkListStore *LIST, GtkTreeIter *ITER, char *STRING, 
                                        BOOLEAN NEWLY_CHANGED)
{
......
   if (NEWLY_CHANGED)
   {
      g_object_set(renderer, "foreground", "Black", NULL);
   }
   else
   {
      g_object_set(renderer, "foreground", "Red", NULL);
   }

   gtk_list_store_set(list_store, ITER,
                                0, STRING,
                            -1);
//   g_object_set(renderer, "text", STRING, NULL);
.......
}

The problem I have here is that when the color is chaned in the renderer and I set the value in the store to 
a specific ITER then the entire column changes color, I need to have only ONE iter (row) to change color as 
requested.

Any suggestions?

Thanks!!