SDXL 1.0 epoch 20 has been trained on google colab, it's not good as the teeth/etc isn't aligned to the uvmap l4d2 common infected uses.

Newer versions will have the colored images inverted for different contrast for training purposes, invert the image for l4d2.

This model is designed to generate left 4 dead 2 common infected textures.

The "colored" images is what Left 4 Dead 2 uses for it's common infected Zombies

the masks work on a grayscale range, 0 to 50 is 1 mask, 50 to 100 is a 2nd mask.

red channel : Specularity | Dirt

green channel : Reflectivity | Blood

blue channel : masking between two gradients (gradient not included with model)

Actual l4d2 textures has the images in a 2x2 texture sheet but I trained them separate.