Is this the code you are actually using or is it a stripped version?
One things you could test doing is having a sub like this: 
sub format_cell3 {
  my ($self,$format) = @_;
  $self->{cell_format}[0]{bgcolor} = $format->{bgcolor};
}

[download]
If this simplified case still doesn't work then something is definately wrong.
In your assignment you should only need this initital -> and from there on you simply have a HoAoH to deal with.

In reply to Re: Strange method behavior by repson
in thread Strange method behavior by Trimbach

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