The psychophysical investigation on the oqaque surface color by the margined variety group of tulip and its meaning on the plant breeding are presented here.
1. Moon & Spencer's theory of color harmony may apply to the plant color.
2. The value of "Aesthetic Measure" arisen from the every part of petals are different even a same flower.
3. The variety showing the high degree of color harmony has high and equal values in every part of petals.
4. Some indications are given of the psychophysical study of the plant color.