Automatic Train Painter [0.17 - 1.1]

To install the mod, you need to copy the files to the folder "C:\Users\{USER_NAME}\AppData\Roaming\Factorio\mods" or use the special FMM program (factorio mod manager). If a mod is missing from the requirements, please let us know in the comments.

Trains will automatically be colored, based on the contents of their inventory, as soon as they begin to move in Automatic Mode.

Item colors are based on their icons, while fluid colors are based on their appearance in pipes, storage tanks, and barrels. If a train's inventory contains multiple entities, their colors will be blended proportionally to the quantity† of each entity present.

Perfect for keeping Logistic Train Network trains color-coded! LTN trains may‡ also be painted when dispatched from depots, based on the item(s) requested.

Settings:

Paint locomotives. It is [ON] by default. When turned off, previously painted locomotives will remain painted in their respective colors.
Paint cargo and/or fluid wagons. The latter works only if using a mod like Fluid Wagon Color Mask.§ They are [OFF] by default. Turning these functions off after having already painted wagons will cause them to return to default colors after stopping and starting again in Automatic Mode.
Unpaint empty trains. This will set the locomotives of an empty train and its wagons to their default colors. It is [ON] by default.
Unpainted locomotive color. The default color for an unpainted locomotive, it can be any 3- or 6-digit hexadecimal number. Default is E4D1C7, original red is EA1100.
Unpainted cargo wagon color. The default color for an unpainted cargo wagon, it can be any 3- or 6-digit hexadecimal number. Default is 6D3A00.
Unpainted fluid wagon color. The default color for an unpainted fluid wagon, it can be any 3- or 6-digit hexadecimal number. Default is C8C8C8.
Enable/input custom colors. See the FAQ page for more details.

Other Features:

Locomotive Equipment Grid: an unused feature of vanilla Factorio, this can now be enabled for locomotives via a Startup mod setting. By default a 2x4 grid large enough to fit a pair of 2x2 equipment modules (e.g., FARL and/or Shuttle Train) simultaneously, it can be extended to 16x16 if desired.
Manual Color Module: an inexpensive 2x2 equipment item that can be placed in the locomotive Equipment Grid. Trains with this item present will not be automatically painted, and will have manual colors preserved. It is researched with Automated Rail Transportation and costs 1 Electronic Circuit. It also provides 1 W of bonus power to the train, for reasons.
Station painting is not included, but can be done via the Automatic Station Painter mod. Thanks to doktorstick for creating this functionality as a standalone mod!