Using terminal sequences, I can colour text in a terminal emulator:
$ echo -e '\e[37;41m--this is white on red--\e[0m'
And this works.
The following prints a red rectangle, i.e. space characters have a red background and an empty foreground:
$ echo -e '\e[37;41m \e[0m '
But the following prints two red rectangles separated by a tab:
$ echo -e '\e[37;41m \t \e[0m '
That is, the tab character does not receive the red background highlighting. It takes the default terminal background colour.
Why isn't tab highlighted like space? Can I force this some other way?