Blue is the colour…
…of money. I bought a 10mm Hex wrench from Park Tools because I needed to remove the freehub body on my bike. When it arrived this morning, I was admiring it’s engineered precision and the ergonomic design of the handle, when a note on the packaging caught my eye.
“The color BLUE is a trademark of Park Tool Co”.
So you can trademark colours? I’m off to trademark a rainbow and sue nature.
...ravings from the Shell... 
Who is Sue? lol sheesh *runs out to trademark universe*