The site moderator says that ‘Hats’ are oversimplified shorthand for whether an activity contravenes a SE’s ToS and other guidelines. Given their deliberate vagueness he would classify most webdev activities as ‘grey’ hat. Further most, SEO tools are not fit for purpose as they tend to mix data sources or derive conclusions about one SE with data from another – a meaningless exercise, according to him.
http://www.cre8asiteforums.com/forums/index.php?s=6d24ae26f7e293e6f265c413fab3c726&showtopic=72102