Mistletoe, V. coloratum, produces mature fruits of two different colors. To characterize the fruit color dimorphism and its geographic variation, we surveyed 23 populations spanning 10 latitudes in Northeast China and recorded 41 species of host plant, 2896 individual hosts, and 6641 individual fruiting mistletoes. The proportions of different color-morphs were counted in each population. In addition, we examined the variation in spectral features of the two color-morphs within and between populations, finding more red-morphs at high latitudes and more yellow-morphs at low latitudes, instead of the expected 1:1 ratio. A strong correlation was detected between the proportions of color-morphs and latitude of the population. The spectral values of the red-morph fruits were significantly correlated with the latitude of the population, while the yellow-morph showed no such correlation. We propose two unexclusive hypotheses—the food-finding strategies hypothesis and the ecological fitting hypothesis—to explain the maintenance of fruit color dimorphism and geographic variation of patterns in this species.