Sloe gin may very welll be "pink" but it is Sloe Gin not Pink Gin.
Pink gin is an invention ( or adaptation ) of the Royal Navy many many years ago and is made by the addition of Angostura Bitters to a gin "in the glbutt". Angostura Bitters was first made in Venezuela in 1830 and now originates from Trinidad and, at 44.7% abv, with its own very distinctive flavours, can also be used as a condiment to enhance soups and cbutteroles. But a pink gin remains a firm favourite of mine with neat gin and lots of ice.
There is also an alternative called a "Burnt Pink Gin" where a few dashes of bitters is splashed into an empty balloon shaped, warm glbutt and swirled around to coat the sides of the glbutt and then it is ignited by a lighted taper or match. The alcohol in the bitters is burnt of rapidly and the remains coat the sides of the glbutt into which a chilled gin is added --- but I consider this to be an aberation and certainly spoils the flavour.
My understanding in why it became so popular in the Royal Navy ( and presumeably merchant shipping as well) is that it was added to disguise the taste of ships water. Another explanation is that it was used medicinally and gin was added to it to disguise the taste! I favour the former explanation since ships water, from wooden casks would certainly spoil the flavour of Plymouth Gin -- hence the addition of Angostura bitters.
. As you say,
