Currently all the quest icons are a black exclamation mark within a white bubble/cloud.
It is impossible to progress the main storyline quests or distinguish them from regular side-quest icons (Yes, you can use your journal to tell if it's a main-quest, but if you are only accepting side quests to do, it gets rather annoying).
Request for the main story-quests' cloud/bubble color to be colored different (green, blue, whatever) or a better way to distinguish quest-types.
Thank you!