Pasting from excel.

Sorry, my english is very bad.
This is my question:
I understand that pasting from excel to CKEditor, the "background-color"(Style) of the columns, doesn't be lost.
But when i copy the excel to Ckeditor, the "background-color" of the excel columns, disseapears.
I had used this page "http://ckeditor.com/demo" to have more reliability in the test,
Does Anyone know anything about it?.
Thanks