



This is the fifth of my rainbow colors in response to Becky’s April Squares challenge theme of ‘Bright.’ (See more responses here.) It’s also where I get into trouble. Cyan? What’s cyan doing in a rainbow? What happened to blue?
Well, blue is coming. What’s gone is indigo. The traditional rainbow colors are red, orange, yellow, green, blue, indigo and violet. These colors were assigned by Sir Isaac Newton way back in the 1600s. In fact, he started with just five colors – red, yellow, green, blue and violet. Later, he added orange and indigo to the color spectrum. These days though, what Newton called blue is today called cyan, and what he called indigo is now called blue.
In reality, there are no bands of color in a rainbow. There’s a continuous gradation of color. The bands are seen because the human eye is limited in the colors it perceives. Converted to black and white, the bands dissolve.
So, for my rainbow colors, I looked at my photos and what I see are red, orange, yellow, green, cyan, blue and violet. Of course, if you look at the colors on the inside of a rainbow, you’ll see they keep going, back through the same sequence. And where the red of this supplementary rainbow overlaps the violet of the primary, the result is more of a purple color.
Having labored through all that, today’s rainbow is a small, bright segment on the ocean, with a black and white version of the same image. Then we have a patch of sand underwater, showing different patterns and colors. Finally, a bullethead parrotfish, bashes its beak on some coral in its pursuit of food.


























