Any object which allows light to pass through it is known as a transparent object. The color of any transparent object is the color of the light transmitted by it.
Ordinary window glass appears white because it allows all the colors in the white light to pass through it.
A red rose appears red in white light because it absorbs all colors except red. But when the same rose is seen through a green filter it appears black because the red color of the rose is absorbed by the green filter.
