Noise

Noise isn't "Noise", in Synthesizers Noise is often used for pink or white Noise, which is a constant level of (all) random frequencies in the full spectrum. the "colour" comes from the slope of filtering. white noise is almost unfiltered but the "darker" the colour gets the more the LPF is applied (higher slope) like pink noise is filtered at 3 dB / Octave. Red Noise is filtered even more, same as brown noise (filtered even more..)