This page contains many lore elements that are not considered part of the new, official lore. It's very unlikely that it will still be considered canon for new lore, but will maintain relevance in old lore.
Coolant is a type of liquid found in computers within the Dataverse, and is essentially the Dataverse's "water". However, unlike actual water, coolant is thicker and harder to swim in. When a bit of plain coolant is held, it forms into an orb called a Coolant Drop. Coolant can only be found in abundance within computers that have coolant systems inside of them. If a computer lacks a coolant system, there will be a minimal amount of coolant in the computer.
The color of coolant can vary across different computers, and in most cases these color differences are merely cosmetic in nature and do not indicate the quality of the coolant in any manner. However, in some cases, coolant in different computers can taste different and also have different health effects on whomever tries to drink the coolant. Usually, coolant is fairly safe to drink raw and unfiltered regardless of color (but can still come with health risks - especially if an individual is not used to drinking raw coolant - similarly to drinking water from a pond), however, in certain computers such as Shy, Hatra, and Muscle computers, the coolant is polluted with harmful materials or has too many other natural substances within it, and thus needs to be filtered heavily in order to be consumed safely. In various computers, buildings such as Coolant Refineries are used for coolant filtration.
There are multiple ways to prepare coolant for consumption besides drinking it raw and/or plain. It is possible to add flavors to coolant to create beverages such as Fizzy Coolant, which, according to DuncanDunclub, is the Dataverse equivalent of flavored sparkling water.
There is also evidence that suggests that like water, coolant can take on multiple natural forms in the Dataverse, such as forming into coolant ice and coolant snow. For instance, according to what DuncanDunclub has said in private, in Muscle computers, "[...] most of the time [coolant will] have a frozen surface", indicating that coolant can freeze and thaw like water.