They following is from a short story I'm writing. The main character and his friend are sitting in a bar while discussing about the the former's wife:
“I see,” he said, thinking this over, as if trying to solve an intricate puzzle. “You must have really upset her. But weird, it seems like she hasn't told anything to my lady. They tell each other everything, you know that. And the strangest thing is that she acted normal when she came to the house yesterday. She just avoided talking about you. Well, that's the extent of what I know. Sorry. Wish I could be of more help.”
I told him it was OK. That this was something I had to deal with myself. We didn't say anything for a while. I watched the fluorescent light of the counter pass through my glass and split itself into a rainbow. I fixed my eyes on it. Curiously, when you grab paint and mix all the colors together (in equal amounts), you get the color black. In this case, however, the combined result was white. I wondered which one was the real nature of rainbows.
“Anyway, it'll pass.” Mr. Kondo sipped his Corona. He drank nothing but beer. “Women are cyclical creatures. The moon rises and sets, the tides go up and down. After they've gone through the full cycle, they always come back. So don't worry too much.”
I'm not sure if I'm being clear enough, or whether the passage is confusing. What I want to say is that when light is split you get the colors of the rainbow, but when you mix many colors together you get black. Which is a bit strange (at least for the protagonist). This can be interpreted as the character wondering what's the true nature of the human heart: light or darkness. This reflects his own behavior: he isn't sure if telling his wife about his perverted fantasy makes him posses a dark, twisted heart.