I feel like it is important to clarify about genres (tags) since some people select what manga to read based on genres categorization.
I suppose my genres indication is more like tags. One of the inconveniences that I’ve found in most of the online manga reading sites is that some tags on the manga title are missing or misleading. For example, a romance-tagged manga might have no sign of any romance 50 chapters in, or the abuse of drama-tags. All of these makes finding the type of manga one is searching for a difficult task.
Therefore, I strive to provide comprehensive and accurate tags for each manga on the countdown list. On the genres list, the colored ones are the genres I think that particular manga has a lot to do with (for example I tagged FMA with Action, Adventure, Fantasy, Drama, Shounen, Military. The colored tags are more central to FMA).