Abstract
From the colorimetric considerations the following two theorems are proved mathematically.
A. The maximum luminous efficiency for any colored light is achieved from the appropriate combination of two spectrum colors.
B. The mixture of two spectrum colors, which gives the maximum luminous efficiency for a colored light, also gives the maximum luminous efficiency for all the colors which can be produced with combinations of these spectrum colors.
A new type fluorescent lamp, named fresh white, which has a slightly greenish color has been developed on the basis of these theorems. The high output 110 W lamp of this type is as efficient as 91 1m/W. Because of its moderate color rendering property this lamp is suitable for street lighting.
