Are Allpass Filters Really Colorless?

Allpass impulse response only ``colorless'' when extremely short (less than 10 ms or so).
Long allpass impulse responses sound like feedback comb-filters
The difference between an allpass and feedback-comb-filter impulse response is one echo! $\begin{center} \epsfig{file=eps/allpasscombir.eps,width=5in} \\ (a) $H(z) = \frac{0.7+z^{-7}}{1+0.7z^{-7}}$ (b) $H(z) = \frac{1}{1+0.7z^{-7}}$ \end{center}$
Steady-state tones (sinusoids) really do see the same gain at every frequency in an allpass, while a comb filter has widely varying gains.