Is it common/good practice to scale down faces in the UV Editor to fit into 1 pixel to have a normal diffuse? First of all, apologies if my question seems too basic to you, I'm a programmer working on a mobile game who's learning how to use Blender and would like to do it correctly. 

Basically I'm making a low poly game and I'm using a 32x32 texture for my model which I use as a colour palette. I'm doing so by unwrapping the object and assigning the faces to a single pixel by scaling them down on the colour I want those faces to be. I was wondering, is this the right way of assigning a single colour to some faces? Can scaling down to 1 pixel affect performance on more complex models? And if I'm doing things incorrectly, what's the best practice for this?

Screenshot below to give you a better idea of how I'm doing this at the moment.



Thank you for taking the time to read and reply,

Simone
Your approach is fine. If it works in tests, stick to it.

Changing (scaling down) the uv coordinates, won't affect your performance at all. If you can update the palette easily, your method has many advantages.

Make sure, you disable interpolation of the texture in your game engine. You want to keep it sharp. In Blender internal renderer (as an example), these filter setting are required, to keep the texture pixelated.



The usual is to assign different materials, with different colors to their respective faces. In Blender this is done by creating new material slots in the material properties panel and then assigning them by selecting the mesh's faces in edit mode and pressing assign with the material slot selected.This will export to most formats and engines.