Sea moss looks like algae. Depending on subsequent processing, smell and color may change.
Irish moss differ by strong, sea-like taste. That's why best way to use it starting from small amounts and apply moss in recipes for mixing the taste with others or to decrease it.
Preparation makes perfect. The right way to prapare sea moss is washing it and rinse before making a gel. In this case you highly decreasing intensity it's taste, so there won't be a problem with it.