QUOTE : We only know colors by relationships. Your father likely pointed to hundreds of objects whose only common feature was the color, and eventually you understood that the commonality of color equaled the word he used. A lot of things are that way, abstract ideas that have no object to define them. Right and wrong, for example. Problems tend to occur when people are eager to fill their cups and accept ideas by those who might be, metaphorically, color blind. Once an idea is learned, once it settles in, it becomes comfortable and hard to discard, like an old hat. And trust me, I have many old hats.