I have some working code now, but my buttons are each a unique name. They are $button1 through $button28. Here's the code that works and the sub for the first button: 
my $button1 = $mw->Button(-text => "18-Letters",
                          -command => sub {print OUTFILE "18L\n"},
                          -command => \&change)->pack(-side => "top");
sub change {
 $button1->configure(-background=>"yellow")
}

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Aside from coding a sub for each button, could I use a if then to configure for an array? The goal is to change the color of the button once it is pressed. 
 
my @btn = $button1-$button28;

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In reply to Re^2: Change button color with Tk by PerlCowboy
in thread Change button color with Tk by PerlCowboy

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