In multi-layer PCBs, inner layers provide essential capabilities beyond signal routing. Power planes and floor planes are focused layers that give lower-impedance power distribution and return paths, respectively. These planes offer various pros: ---Exactly what are the color options for PCB solder mask? Eco-friendly, black, blue, purple, yellow, white etcetera https://metalpcbcopperbasedboard06159.ourcodeblog.com/31371762/considerations-to-know-about-6-layer-one-stage-led-small-pitch-display-pcb-board