According to the fluff, the Tau use appropriate camouflage for the environment they are fighting in. This means that you could use pretty much any paint scheme that you want, as long as you come up with a backstory for why this serves to blend into the environment. There are however several schemes that relate to the Septs (home worlds) of the Tau, and could also be considered the “parade” schemes for these Septs. The 8th edition Tau codex shows quite a few applied to a Crisis suit (the 4th edition Codes had several applied to Fire Warriors). But I think that only a few schemes have ever been applied by GW as “studio scheme” to a full army:
The original paint scheme is the T’au desert scheme of ochre armor and dark brown fabric. This scheme is still featured on several miniatures on the GW site, such as this Cadre Fireblade:
The 4th edition codes featured quite a large army in the Sa’cean urban scheme of greyish blue, to which the orange Sa’cea Sept markings are a nice contrast. I like this scheme a lot, and would be my go-to choice for an urban-style Tau army:
The current “official” scheme is the white and black scheme with the red markings of the Vior’la Sept. This scheme has a certain Stormtrooper feeling to it. It certainly stands out on a table, but it isn’t very camouflage to me. As snow scheme, I prefer the Bork’an scheme shown in the 4th edition codex.
Finally, there’s the red Farsight enclaves scheme. This is attributed to the red planet on which Farsight resides. It’s a nice scheme when executed well, but has more of a parade than a camo feel to it.
Each T’au Sept (home world) has its own color. This color is used for the markings on the armor, and is used to denote rank. According to the 8th edition codex, this is done on Crisis suits in this manner:
- Shas’ui: sensor vane (antenna and left shoulder on Fire Warrior)
- Shas’vre: helmet and sensor vanes
- Shas’el: helmet only, sensor vanes in armor color
- Shas’o: helmet and sensor vanes, markings in armor color
The 8th edition codex lists 21 Sept colors. The best-known are the white of T’au, orange of Sa’cea, and red of Vior’la. I’ve found this summary, including paint names, on Reddit:
The Tau use stripes and dots to signify to which team and cadre a trooper belongs. These are painted in the Sept colors, except for those on a Crisis suit Shas’o helmet (see above). There’s no official definition of how this works, but a user on AdvancedTauTactica has devised a scheme:
The official GW Tau decal sheet (which has red markings, i.e. suitable for Vior’la only) can also be used as a guideline.