The Canadian Viceregals are the de jure official representatives of the Monarch of Canada currently, Queen Elisabeth II. There is a Governor-General which represents the monarch at the federal level and Lieutenant-Governor which represent her on the provincial level.
Despite the title, Lieutenant-Governors are not technically subordinates of the Governor General but representatives of the monarch in their own right. This is due to the nature of Canada as a confederation of provinces with the federal and provincial government having their own, separate sphere of powers. Having separate viceregals was a necessity to allow the "crown" of each province (and the federal government) to operate independently and for the good of those it represent when a conflict might arise such as one province suing another.
The governor general is entitled to wear a version of the so-called windsor uniform, a uniform introduced in the 19th century to be worn at court by civil servants, diplomats and other civilians who did not currently belonged to an organisation with an uniform. It is navy blue with gold embroidery on the chest, collar and cuffs.
The windsor uniform fell out of favour in the later part of the 20th century with most governor-general attending official function choosing to wear either an evening suit or a military uniform in the case of Armed forces related events.
The military uniform worn by a governor general is the same as general officers but with a gold aiguillette hanging from the right shoulder, the Canadian crest (a crowned lion holding a maple leaf) worn on the shoulder straps & an arrangement of Canadian crests alternating with gold leaves between 2 gold bands on the cuffs.
lieutenant governors are also entitled to wear the windsor uniform although just like for the governor generals, it has fallen in disfavour outside of official portraits or the odd ceremony in most provinces.
An exception appears to be British Columbia where Lieutenant governors to this day can be seen wearing some sort of uniforms when performing official duties. Although these were mostly the traditional civilian uniform, 2 attempts at creating a modernised version occurred in that province. The first was Iona Campagnolo who introduced a windsor uniform-inspired black suit that replaced the gold leaves embroidery with more restrained local symbols in silver thread. The other was one of her successor, Judith Guichon, who similarly has worn some silver on black "civilian uniform" during certain official functions.
One element that sometime confuse matter is the fact that some lieutenant-govenors (like some governor-generals) are veterans and might sometime wear their former uniform while other are will wear one in their role as honourary colonels. In neither case these should be construed as "lieutenant-governor's uniform".
The actual badge of office of lieutenant governor is the same regardless of province: A gold and red squarish enameled pin similar to an army rank insignia "pip" with at the centre a gold maple leaf under a gold crown.
The spouse of a lieutenant-governor (whether male or female) receives an identical badge but with the central maple leaf is silver instead of gold.
The post of aide-de-camps is an honorary one meant to recognise the work done by a member of a uniformed service. Although traditionally they were members of the military, aide-de-camps to Lieutenant-Governors have increasingly been chosen from among police, fire department and emergency services within their respective provinces.
Aide-camps when on duty will wear a gold aiguillette (silver for saint-john ambulance members) on the right shoulder if serving a vice-regal or a member of the royal family. This makes them stand apart from aide-de-camps to officers and politicians who wear it on the left.
They will also wear on their shoulder straps the provincial COA with or without a maple leaves wreath (if serving a lieutenant-governor), the Canadian royal badge (if serving the governor-general) or a cypher if serving one of the member of the royal family. The exact position of the badge will depend on the type of rank insignias worn on the shoulder straps, either being placed directly on top (navy, air force and most of Quebec's services) or below (the army, RCMP and most other police forces). The type of badge can also vary from enameled or embroidered.
On a few rare occasions, aide-de-camps have been chosen from non-uniformed services. In such cases, none of the uniform guidelines apply and the aide-de-camp will be recognised solely by the provincial or royal badge worn on the breast or lapel.