It's not like bodies of water are always blue anyway. The ocean's not. I've seen the same broad stretch of the upper Mississippi appear anywhere from pale green

It's not like bodies of water are always blue anyway. The ocean's not. I've seen the same broad stretch of the upper Mississippi appear anywhere from pale green to battleship grey, along with several shades of blue including almost sapphire. The lower part of the Missouri's mostly brown or grey. I'd assume anyone who described it as any kind of blue without apparent purpose or calling attention to how unusual that is had simply never seen it. The later example in TFA of the Bible using the phrase "red horse" is an odd one. There are red horses. Hell Steinbeck wrote a novella titled "The Red Pony". They're pretty common. What's the big deal?