If you want to be sure that the document preserves colors, shapes, alignments - use either .pdf or .html. Period. With .doc, only the program-creator knows what it meant - and even this program can damage the document and destroy it. With .html, you can edit the document in Notepad, vi, nano, emacs, anything, and you see clearly what is going on. With .pdf, nobody can edit it (except, maybe, Adobe Acrobat or PDFedit) - it's make once and never edit, best format for printing.