Well you don't show any code, but here is something to play with. Tab around the widgets, or force focus to a canvas. Otherwise, show a minimal working code example, and say what you want it to do.

#!/usr/bin/perl
use strict;
use Tk;
use Tk::Pane;

my $mw = MainWindow->new;

$mw->geometry('400x250');

my $mwf = $mw->Scrolled('Pane', 
               -scrollbars=>'osoe', 
           -sticky=>'nwse',
           )->pack(-expand=>1, -fill=>'both');

my $f1 = $mwf->Frame()->pack();
my $f2 = $mwf->Frame()->pack();

my %canv;

for (0..4){
  $canv{$_}{'obj'} = $f1->Scrolled('Canvas',
            -height => 100,
            -width => 100,
            -bg =>'white',
        -scrollbars => 'osoe',
        -scrollregion => [ 0, 0, 500, 500 ], 
   )->pack(-side =>'left' ,-padx=>10,-pady=>10);

  $canv{$_}{'obj'}->createText(50,50,
    -text   => $_,
    -anchor => 'center',
    );

my $num = $_;
$canv{$num}{'obj'}->CanvasBind( '<FocusOut>' => sub{
           $canv{$num}{'obj'}->configure(-bg=>'lightyellow');
   } );

$canv{$num}{'obj'}->CanvasBind( '<FocusIn>' => sub{
           $canv{$num}{'obj'}->configure(-bg=>'lightgreen');
   } );
}

for (5..9){
  $canv{$_}{'obj'} = $f2->Scrolled('Canvas',
            -height => 100,
            -width => 100,
        -bg =>'white',
            -scrollbars => 'osoe',
        -scrollregion => [ 0, 0, 500, 500 ], 
   )->pack(-side =>'left', -padx=>10,-pady=>10 );

  $canv{$_}{'obj'}->createText(50,50,
    -text   => $_,
    -anchor => 'center',
    );

my $num = $_;
$canv{$num}{'obj'}->CanvasBind( '<FocusOut>' => sub{
           $canv{$num}{'obj'}->configure(-bg=>'lightyellow');
   } );

$canv{$num}{'obj'}->CanvasBind( '<FocusIn>' => sub{
           $canv{$num}{'obj'}->configure(-bg=>'lightgreen');
   } );
}


my $button = $mw->Button(-text=>'Focus 1',
   -command => sub{
       $canv{1}{'obj'}->focusForce;
       $canv{1}{'obj'}->configure(-bg=>'blue');
     
     })->pack();


MainLoop();
[download]