Minecraft wiki entry for Redstone_tips, associated text: If you don't want to use wool, concrete, or terracotta, you can find other blocks that are different colors from each other. For example, you can use stone variants and wood-related blocks. However, try not to use blocks of similar color, such as a block of coal and black concrete on 2 different parts of a circuit. You can also use different colors or variants to mark switch-supporting blocks (input) or potential output locations for a circuit, e,g, if most of the circuit is built on stone brick, you might choose carved stone brick for switch blocks, polished granite for output locations, and diorite for mobile blocks. Glass (which can also be tinted) can be used to display the workings of a circuit; it can also make sure that lava and water (e.g., in a cobblestone generator) are visible but not open to unwary players.