We propose a broad-band colored noise, which allows the transition between
''red'' and "green" noises. A double-integral algorithm for solving the Lan
gevin equation with this noise is developed. The steady currents of an over
damped particle moving in the correlation and diffusion ratchets are calcul
ated. It is shown that the flow reverses sign when the external noise is fi
ltered off in the region of low frequencies to a sufficient extent. The pre
sent noise is also compared with the Ornstein-Uhlenbeck colored noise and t
he harmonic noise. [S1063-651X(99)12112-3].