Users can now append an optional two letter token to the callout label, > [!progress bl] for blue, > [!progress pi] for pink, across fifteen colours. The design decision worth restating is that the token rides inside the callout label itself, which Obsidian passes straight through into the data-callout attribute. That means the plugin does no styling work at all. It only has to parse the token and write it back unchanged when it regenerates the line, and everything visual is one attribute selector per colour in CSS, each setting a single --pb-accent RGB triplet that the base rules and the light theme derive from.