Thanks for the reply. You helped to find the problem.
It appears that somehow Windows Photo Viewer saves its own copy of printer options.
There was a time when the color cartridges on my printer started getting low.
So I decided to try to print in "black only" temporarily, until I could get the color cartridges replaced.
I changed the option in the preferences for my printer, where I had done it before.
I must have printed something with Windows Photo Viewer while it was set this way, and Windows Photo Viewer must have saved its own copy of the printer options, because when
I replaced the color cartridges and changed the option back in the preferences for my printer, other programs, such as Word and Paint, printed in color properly, but Windows Photo Viewer kept on printing in "black only", until I changed the printer options
in Windows Photo Viewer itself. Then it started printing in color again.
I think this is pretty amazing.
I have a screenshot that shows the printer option set two different ways simultaneously. If you would like to see it, please give me somewhere that I can upload it to.