Abstract: To identify colors of objects as natural as those seen in naked eye view, it is provided a method of designing a colored lens specified by color coordinate values L, a, and b in a uniform color space, including: selecting a=+0.35 and b=+3.0 in L=87.4, a=?0.25 and b=+1.6 in L=74.2, and a=+1.5 and b=+3.35 in L=49.9 as target values in an a-b plane determined from the L-value, respectively; setting ?4.3?a?+5 and ?3?b?+9 in L=87.4, ?3.5?a?+3 and ?5?b?+8.2 in L=74.2, and ?1.5?a?+4.5 and ?0.5?b?+7.2 in L=49.9 as deviation ranges, respectively; forming an allowable range by connecting vertexes of the deviation ranges in L=87.4, L=74.2, and L=49.9 by second-order polynomial approximation curves in the uniform color space; and selecting the values L, a, and b of the colored lens so as to be included in the allowable range in the uniform color space.

Abstract: To identify colors of objects as natural as those seen in naked eye view, it is provided a method of designing a colored lens specified by color coordinate values L, a, and b in a uniform color space, including: selecting a=+0.35 and b=+3.0 in L=87.4, a=?0.25 and b=+1.6 in L=74.2, and a=+1.5 and b=+3.35 in L=49.9 as target values in an a-b plane determined from the L-value, respectively; setting ?4.3?a?+5 and ?3?b?+9 in L=87.4, ?3.5?a?+3 and ?5?b?+8.2 in L=74.2, and ?1.5?a?+4.5 and ?0.5?b?+7.2 in L=49.9 as deviation ranges, respectively; forming an allowable range by connecting vertexes of the deviation ranges in L=87.4, L=74.2, and L=49.9 by second-order polynomial approximation curves in the uniform color space; and selecting the values L, a, and b of the colored lens so as to be included in the allowable range in the uniform color space.