The effect of colored noise on circadian oscillation and internal signal stochastic resonance(ISSR) has been studied in a Neurospora circadian clock system. The result shows that the correlation time of colored noise can affect strongly the strength of ISSR. For the case of no external signal(ES), the correlation time of colored noise plays a suppressive role for ISSR, and the suppressive role is increased with the increment of correlation time of colored noise. When the ES is injected to the system, with the increasing of the correlation time of colored noise, not only its suppressive role for ISSR is increased, but also the single peak ISSR can be transformed as internal single stochastic bi-resonance(ISSBR). There exists an optimal frequency of ES for the ISSR information amplification, while the ISSR is suppressed for another frequency of ES. In contrast to external colored noise, internal colored noise is more efficient to sustain and amplify the ISSR information. Furthermore, there exists a critical noise intensity for destroying the difference between white and colored noises.