- $out .= '<tbody>';
- my $col = 0;
- my $colbreak = scalar map { @$_ } @colmap; # same width as hue rows
- for my $num (sort { $greymap{$a} <=> $greymap{$b} } keys %greymap) {
- $out .= '<tr>' unless $col++ % $colbreak;
- $out .= colcell($num, ($greymap{$num}) x 3);
+ if (%greymap) {
+ $out .= '<tbody>';
+ my $col = 0;
+ my $colbreak = scalar map { @$_ } @colmap; # same width as hue rows
+ for my $num (sort { $greymap{$a} <=> $greymap{$b} } keys %greymap) {
+ $out .= '<tr>' unless $col++ % $colbreak;
+ $out .= colcell($num, ($greymap{$num}) x 3);
+ }