Modern chargers use more solid state components to control the charge rate, output voltage, and back voltage when the charger is unplugged. They likely use a diode bridge that may or may not have the large power diode like the old ones have. The more electronics there are, the more vulnerable to failure the unit is. Most garage spaces or shop buildings are lucky if they have a heater let alone an air conditioning system. The lack of climate control also makes electronic equipment vulnerable if the humidity is too high. The older chargers generally have a multi-stage set up of power coils with a switch to control voltage output, an amp meter, and the power diode or diodes to act as a one way valve for current to prevent back flow if left connected with the wall plug pulled. They can take a pretty harsh environment.
Coloring the wiring for identification in motor vehicle design is the easiest way to ID the wires of the different circuits. Most automotive wiring is just for half of the system circuit and is generally just the power part of the equation. The ground plane made up of all the steel or aluminum structure of the car provides that unless the body is of a non conductive material like fiberglass. In that case, it would require ground wires to the frame structure to complete the circuit.
In aviation, 99% of wiring is specially coated wire of adequate gauge that is all white in color. The manufacturing regulations require the wire to have a code printed on at 6 to 8 inch intervals for identification. The number letter code tells what system it's for with an individual number and gauge code for each separate wire. The circuit diagrams show the code of each wire and the terminal blocks are all lettered or numbers for connections. This also applies to switches, components, and other connections of the circuits like plugs and individual single wire connectors. Everything is code numbered and located by diagrams. The only bad thing is that the codes are small and hard to see for old men like me plus they deteriorate over time that even makes it more fun to ID. The color codes don't seem too bad but the cloth covered wire types deteriorate as well and pretty quickly where the wires are exposed to the light of day.