The "Texture" section of the Stronghold 3 editor allows you to add additional textures to your own Stronghold 3 map. The main goal of this is to make the map look better itself.
On the textures page, you have the choice of using Grass (default texture) Rough Grass, Sand, Dark Mud, Stones, Cliff, Dry Mud and Courtyard textures on your map. Additionally, you can choose the size of your brush and have a variety of different ways the texture can be applied, for example, circle paints the texture on your map much more than smooth does, and for a more sporadic effect you can use a different brush type called "noise 3". However, the intensity affects how heavy you paint on the map. The less the intensity, the lighter the texture you paint. For this reason, you have a much bigger ability to make the textures exactly how you wanted them, which all the previous games of the series did not have.
Additionally, there is one other sub-section in the textures section itself, which is called "Tint". This is for the colour of the texture you add to your map - you select a colour, then add your texture to the map, or even just paint over an existing texture and you can see how Tint brightens it up:
But perhaps the most impressive part of the textures section of the editor is the fact you can create your own custom tint. By selecting "custom colour" and then "define custom colours" you can set your own tints which can be used on your map. Note however, that once the editor is closed, your custom tints will be lost. Make sure you save the colour ratios in case you need to use them again.
In Stronghold Crusader 2, food production buildings can only be placed on "Oasis" textures. The three types of Oasis textures include "Oasis (Feather)", "Oasis (Grass)" as well as "Oasis (Leaves)".
In the editor, you have the ability to place fully-functional food production buildings anywhere. However, in-game they must be placed on Oasis. This allows you to circumvent the restriction of placing purely on Oasis.
The default texture is "Sand (Base)". The other textures are simply textures which can be planted anywhere. All textures are as follows:
The "Tinting" and the brush sub-sections do exactly what the ones from Stronghold 3 do.