Tricky one… Then you’re limited to what can be done using UVmap on Explode and mask image or blend texture. Image node output can be used to mix materials or colors. Created mapping coordinates can be additionally randomized using some node math if needed.
pretty much the same setup as it was in blenderdiplom tutorial.
To get transparency going you can reuse last Mix node’s setup in previous image; instead of Colorramp going into Mix Fac input connect Image texture node and use some ramp image or plug Blend texture node. You probably will have to tweak maping of blend textures.
Alternatively, use Cell fracture addon on your object/particle system and nodes from my previous post - then you will have particle objects (yes, you’re correct, i did use this).