Yup depends on material. Frequency and energy aren't dependent. Human eyes typically have only three color rods, sometimes four...yellow ones.
Awesome idea having different laser colors
EDIT I was wrong, the energy and frequency are directly proportional. Inversemto wavelength
From what I remember of basic physics the energy of an individual photon is proportional to the frequency, but that's all. There's nothing stopping you in theory from making a stupidly powerful laser with red photons - you just need an awful lot of them. In practice there are issues of efficiency, overheating and other boring problems, but this is 3301 and I think it's more than time for as many laser colours as my monitor can handle.