The purpose of the study is to measure the apparent colors by area effect under the sunlight for color planning of structures.
We considered the method of measure the apparent colors by area effect under sunlight, and measured the 23 colors, 5 types size, on the condition under the direct ray, and without the direct ray. The result is as follows; 1) Under the direct ray, the apparent colors of large size sample is seem more brightness and vivid than object colors. The value rise 2.5 and the chroma rise 6 (maximum). Without the direct ray, the apparent colors is seen the same as object colors. 2) The deference between apparent color and object color is influenced by chroma and value of the sample. 3) Compared with indoors, under the direct ray, the raising of chroma of the apparent colors is more big. 4) It is showed the relation between the illumination and the apparent color in a day.