Colors are defined by the length of electromagnetic waves. Certain wave lengths are reflected off an object back to our eyes, which we then receive as a certain color. If an object absorbs all wavelenghts in the color spectrum, then we preceive it as black, or the absence of color. If all wavelengths are reflected back to our eyes we preceive it as white, really not a color. But what about in between - that is grey. Color or not?
fbzrjurer ba gung uvyyfvqr va gur guvpx jrrqf, ybbx sbe n pyhfgre bs fznyy ebpxf.