"True" pink noise is likewise impossible: if it's equal energy per octave, then since there is no "lowest octave," any energy in any octave implies infinity at 0hz. The fexpr~ approach I gave accumulates, but imagines a "container" with "walls" at +/- 1.0 where whatever was doing the random walk "bounces" off the wall. It should have a color within auditory range similar to unrestricted integration. A lot depends on what you want to do with the noise (it's not necessarily an audio source).
Convolution is a pretty good way to go. I've seen a number of filters that try to distribute phase randomly across the frequency magnitude curve. Also remember that the 6dB dropoff is with respect to log frequency, whereas FFT is linear in frequency.