will the energizer lithiums make the color of the blade brighter or just get more use out of the batteries ?
They might make the saber a bit brighter. I don't know how much difference .3 volts makes. You'll get more use also compared to standard alkaline, but NiMH's well give you the most use(each battery can be charged up to 1000 times so your standard 4 pack is like getting 4000 batteries).