^^^^^ This. It's amazing that we both came up with the exact same technique for this. I just filled a solid color in the diffuse, then i used a "Holographic" Map with a black background and a few gray squares and stacked those up with the bump offset like riddla said, If u add them all together you get an additive…
Try to model box in the box and assign aditive alpha blend shader in unity.. I think one of particle should be fine.. When boxes start to owerlap then their color multiply and with subtle glow controled trough alpha.. This wuld by my way of utilizing already build-in shaders. Cheers :) Also try to put noise to diffuse or…