We often need to consider the influence on human perception when we develop an image processing algorithm or design parameters for image processing. The perception of color noise is also important for understanding the human vision system (HVS). Although we can use the CSF to express the property of achromatic noise appearance, it is not so easy to be applied to colors. While the CSF can be explained by a primary color vision, a color appearance is governed by higher order mechanisms. In this paper, we show the quantitative difference between achromatic and chromatic noise appearance. To reveal the perception of color noise quantitatively, we have conducted subjective experiments with modeled achromatic and chromatic noises using the 2AFC method. According to the results, it is shown that the ratio of luminance noise sensitivity to color noise sensitivity is 10⁰-10² depends on their spatial frequencies and background colors.