Objective To detect the color damage in patients with idiopathic optical neuritis (ION) after the treatment. Methods A total of 26 ION patients (44 eyes) with ION whose visual acuity were above 1. 0 were collected. All the patients had undergone the treatment of incretion and had the visual acuity more than 1. 0 after the treatment. The results of MRI and blood examination were normal. Another 24 healthy persons were selected as the normal control. Total error scores (TES) and each error score of red, green and blue were measured via Farnsworth Munsell-100 hue tester. The TES origin scores and their square roots were used for a statistical analysis. The results of the two groups were compared. Results There were significant differences in TES and its square roots between ION group and the normal control group (t=3.079,3. 133;P = 0. 0033,0. 0026). The differences in the level of error scores of each color between the tow groups were not significant (t = 1. 91, 1.15, 1.62;P = 0.061, 0.26, 0.11);but the differences in the square roots of red color between the two groups were statistically (t=2. 21, P = 0. 031).Conclusion After the treatment, the visual acuity of ION patients increases, but the color damage still exist;red color damage happens first.