UPDATE — The Wall Street Journal (via @sarablask) explains what happened:
Across our printing network a few locations are unable to accommodate full color capacity. Unfortunately, that resulted in an all-black map for readers in the Denver, Kansas City, Salt Lake and Albuquerque markets. We apologize for any confusion this may have caused. Our operations team is working to alleviate this capacity issue for future issues.
A Romenesko reader from Colorado sent this Wall Street Journal black and white map, which obviously needs color to show how divided our nation is. (It is in color in my Journal Chicago edition.) Here’s the explanation on Reddit from someone claiming to be a pressman:
As a pressmen who prints the WSJ 6 days a week I can tell you that this particular page was sent to us in color (we work on contracts) but because this edition of the paper was so big due to the election, this press didn’t have room to run every page in color so they had to run some of them in black and white.
On a press, a color page takes up 4 spots (black, yellow, magenta, cyan) and when you’re running such a big edition of the paper, you sometimes don’t have space for color on every page so some pages have to run in BW depending on where on the press they are placed. And when you’re running 2 presses of the same paper (to get it done quicker if you’re doing a lot of copies) that will take up 8 spots. 4 spots for each set.
If we only have say, 4 pages we can change to black and white to make the page fit, we have to pick the page with editorial because any pages with an advertisement needs to run in color at all costs since that space was bought to use color.