The Landscape Act was established and improvement orders could be given on color and design. Local governments now need to establish objective and distinct standard. But the discretionary standard such as the harmony with the neighborhood as well as the quantitative standard are used in official landscape plan. Besides, accent color as well as base color is prescribed. So this paper deals with the color standard of buildings. How to set numerical value of the quantitative standard of base colors and area of accent color is clarified. In addition, how to judge conformity on discretionary standard is also elucidated.