FesteringDoubt

Hi, We are planning to install a new printer (make and model undetermined) that will be available to students to print out work. the plan is for it to be a colour printer but students by default can only print in black and white, and that through a special code or a teacher doing something they can print in colour. We currently do not have any kind of quota or charging system, but if necessary we can install one. Is there any software, either from a manufacturer or 3rd party that would allow us to do something like this? thanks

Currently my school runs an almost completely HP switch network, but when looking for a replacement switch we couldn't find an exact copy and we couldn't find a HP switch that met our needs and was at a price we could pay so we were thinking of buying a switch from another manufacturer, are there any considerations for this, and any brands to steer clear of/look at closely. Thanks in advance for any advice.