A family of Microsoft word processing software products for creating web, email, and print documents.
Crossing something out electronically is a nonsense; period. That the facility is even made available is a questionable use of resources. If you really want to strikethrough in a colour other than the text colour, you must use fields (see http://wordfaqs.mvps.org/Overbar.htm) to overlay your text with struckthrough spaces, and format the spaces in whatever colour you want.