[gtkmm] Reset a value in a cell

[Igor Gorbounov <igorbounov voronezh serw ru>]

Hi, All!
In my application the color of cells in a TreeView is taken from a special
"hidden" colomn:
"pColumn->add_attribute(pRenderer->property_foreground_gdk(),
               currTableColumns.fcolors[cols_count-1]);"
And before any color values are put into cells of this special colomn
all rows in the treeview have a default look (provided, I suppose, by
window manager); those rows are in stripes of alternative color.
I like these stripes.
So after using some special colors I need to reset the cell colors
to default values.
Is there any way to reset the value in a cell to its default value?
Something like:
(*it)(currTableColumns.fcolors[colnum]).reset_value()?
   Hopefully,
      Igor Gorbounov