-bg is not an option for add(), but you are close, just need to define ItemStyle.

use Tk;
use Tk::Tree;
use Tk::ItemStyle;

use warnings;
use strict;

my $main = MainWindow->new (-title => "Test tree");
my $tree = $main->ScrlTree(-itemtype => 'text', -separator  => '/', -s
+crollbars => "osoe");
my $red_style = $tree->ItemStyle('text', -refwindow => $tree, -bg => '
+red');
my $green_style = $tree->ItemStyle('text', -refwindow => $tree, -bg =>
+ 'green');
$tree->add(1, -text => 'abcd', -itemtype => 'text', -style => $red_sty
+le);
$tree->add(2, -text => '1234', -itemtype => 'text', -style => $green_s
+tyle);
$tree->autosetmode;
$tree->close (1);
$tree->pack(-fill=>'both',-expand => 1);

MainLoop;

[download]

In reply to Re: Set background on Tk::Tree nodes by pg
in thread Set background on Tk::Tree nodes by GrandFather

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