Colored Noise in Quantum Chaos
  We derive a set of spectral statistics whose power spectrum is characterized, in the case of chaotic quantum systems, by colored noise $1/f^{\gamma}$, where the integer parameter $\gamma$ critically depends on the specific energy-level statistic considered. In the case of regular quantum systems these spectral statistics show $1/f^{\gamma+1}$ noise. 
Luca Salasnich