I made a simple modification to the default Minecraft Texture Pack. The only thing I edited was redstone elements. Redstone torches are red when they are off, and green when they are on. Same with repeaters. The pistons show green under the springboard if they are on. Powered rails are red when they aren't powered, and green when they are. This creates some contrast as to what is on or off, and makes circuitry very clear to understand.

I plan to use these color mods in my next texture pack. I'm about 1/3 done with it. I'll post it when it's done.