Viceroys
Viceroys are individuals appointed by the Senate to manage the affairs of both budding habitable worlds and systems where the Umbrian presence is confined to artificial habitations, and therefore considered impermanent. They serve a standard term of four years, though that term can be renewed at the Senate's discretion.
The Viceroy is given broad leeway in managing the affairs of their assigned system as the chief executive. In that role, they will determine policy regarding resource extraction and utilization, environmental standards, the assignment of government land for commercial use, levy taxes to support their administration, and many other tasks required by colonial life.
They maintain substantial judicial responsibilities as well. They can mediate disputes between parties and are responsible for maintaining basic law enforcement functionality for their jurisdiction.
With that being said, they still cannot infringe on the basic rights afforded to all Umbrians through the Republic's constitution, and therefore are not free from oversight or censure.
While recommended by and reporting to the Triumvirate, the Viceroy is appointed by the Senate, and the legislature maintains oversight through the Colonial Affairs Commission, or CAC. The Viceroy must conduct business in a transparent and publicly visible way, with their decisions open to public comment and recorded to promote accountability.
Skirting these transparency standards is one of the primary reasons why a colony's population may seek to censure or remove a sitting Viceroy, and the CAC gives broad discretion to colonists who allege inappropriate behavior or abuse of power.
While each Viceroy is given significant discretion in how they handle their mandate, many have come to establish councils of key stakeholders, who they can rely on for advice and guidance on key decisions. Those who do tend to be more effective in managing their system's affairs. It also has an added benefit for those governing worlds which ultimately assert their status as full members of the Republic, as successful administrators are often elected to key positions of authority upon the colony’s ascension to self-rule.