[Objective]Sichuan is the area the most representative of purplish sandstones and shales distribution in China. The purpose of this article is to verify whether the hue of "L.C. of purplish sandstones and shales" in Chinese Soil Taxonomy(Third Edition) is reasonable. [Method]In this paper, a total of 45 samples of the parent rocks of typical purplish soils in Sichuan were collected and analyzed for hue in the light of the "Chinese Standard Soil Color Charts" (hereinafter referred to as Chinese Color Charts), and "Japanese Revised Standard Soil Color Charts"(hereinafter referred to as Japanese Color Charts) and with the aid of a spectrophotometer. And then, the data were compared against the purple (RP) definition for "L.C. of purplish sandstones and shales" in the Chinese Soil Taxonomy (Third Edition). Based on this, relevant revisions were suggested. [Result]Results show that when the color of the parent rock samples in block was measured with the Chinese Color Charts and the Japanese Color Charts, the number of the samples conforming to the RP hue reached up to 20.0% and 33.3%, respectively. And when the color of the parent rock samples in powder (ground to pass a 10 mesh sieve), only 2.2% of the samples matched the RP hue in the Chinese Color Charts. When measured with a spectrophotometer the parent rock samples, either in block or in powder were RP-free, and most of them were of YR hue. [Conclusion]Therefore, taking into account the definitions of purplish soil and red soil set by other scholars, it is suggested that the color definition for "L.C. of purplish sandstones and shales" should be revised as follows: hue of 2.5RP ~ 10RP; or hue of 2.5R ~ 5YR, dry value of 3 ~ 6, and dry chroma of 2 ~ 4. Once the revised standard is used, 62% ~ 75% of the samples meet the definition of purple, which is much closer to the traditional understanding of the color of purplish soil. In addition, it is necessary to further improve the soil color charts system, or to use a portable colorimeter that can objectively, accurately and automatically read Munsell color information in measuring soil color. And it is essential to observe more attentively the "purple" color of purplish sandstones and shales during the field investigation so as to avoid negligence of the soil with "L.C. of purplish sandstones and shales".