That part is in the original modding documentation, not the addendum.
To summarize, the data (or "teamcolor", though that is not exactly an accurate term) texture is constructed thus:
You use RGB values to control how the various shaders are applied to your textures.
-Red color value controls opacity of teamcolor areas; the more red a part of the data texture is, the more is that part of your texture tinted in the color of your team.
-Green controls the amount of luminance; the greater the green value, moreluminance is applied to that part of the texture. This is used for glowing parts like windows, engines etc.
-Blue controls the amount of reflection applied to that part of the texture; again, more blue means more reflection. Chrome-like effect is achieved by having a normally dark texture reflect near 100%, for example.
You can also mix and match RGB values to achieve a desired effect. For example, to have your engine ports glow in the color of your chosen team, you would want to increase both the green and the red amounts for that part of the data texture.
One more value to consider is the alpha channel. This controls the amount of bloom, usually associated with the luminous parts of the texture. The whiter a part of the alpha channel is, more bloom is applied.
Hope this helps!