A Color Palette That Prints Well In Black and White

A month or so ago, I ran into a problem while writing some documentation. I wanted to use colors to divide different sections of a screenshot, but I knew that many users would be reading the document after it was printed in black and white. It took me quite a bit of time to come up with the solution, but I eventually found five colors that print as different shades of grey. Here is an image of my findings: