Source for the following: exhibits at the museum I work at, an old Rum and Sugar warehouse in London's old Docks.

So, From 1740 onwards in the British Navy, rum was watered down and had citrus juices (and sometimes spices added) to make Grog. This was to lessen the potency of the spirit and to help combat diseases such as scurvy on the orders of Vice Admiral Edward Vernon. Traditional Navy Rum, from which grog is made is of the dark variety, so one can safely assume that the mariners of this time would be drinking a watered-down dark rum. I say safe to assume, as despite the depth that the Museum goes to with regards to the rum trade and maritime life, no mention is made of the colour of said rum - at least in the public displays.

Add to this the fact that the colour of rum (and most spirits for that matter) is due to aging in oak barrels (plain barrels for golden, charred oak barrels for dark rum) - rum was transported and stored, at least in the warehouse that I now work at, in oak barrels - and it adds weight to the hypothesis.

It would be great if someone with access to other written sources can back this up. I hope this satisfies the beautifully stringent rules on top level answers of this sub. I will be happy to amend or be removed if the mods are not happy.

Edit: talking to one of our guides - in the building where our museum is, Rum was usually stored in barrels that previously aged whiskey, further adding to the colour and flavour. Also, A friend of mine is half Grenadian and made a video of a rum distillery that has been continually operational since the 1800s on the island. I'll post further down if I can find it. Been making rum the same way for 200 years!

Most, if not all, rums from former British West Indian possessions vary from fairly dark to very dark. Some Jamaican rums are lighter in colour, but still brown, whilst those from Guyana are very dark. This being the case I would suggest that British sailors at least would have drunk dark rums. As has already been suggested white rum, like Bacardi, is a fairly recent development. As far as Pusser's Rum is concerned, it is best served with fresh lime juice and a little soda water; ice optional.