Could anyone provide me with an image of the voltage output of an NXT or EV3 colorsensor. I would like to have the analog output if it's possible, and not the digital output.
Depends on what programming software you are using. The education versions of the NXT and EV3 software having data logging features that may be what you are looking for.
The education versions of NXT and EV3 programming software are available for purchase from www.education.lego.com