We could modify the double click behavior: in addition to character classes, it could also look at the attributes (color, bold/italic etc.) and stop where it changes.

This could be useful in a number of scenarios, e.g. with a text editor that's aware of the grammar of the file and uses syntax highlighting, this could result in a better per-language behavior.  E.g. they'd know that \n is a token of two characters that are strongly coupled together, and a double click would select them accordingly.

Also, highlighted output of certain tools (e.g. grep, gcc) could result in better experience.  E.g. I just grepped from a CSV file where some entries contained a ':', now it would have been handy to treat those colons as wordchars, but not grep's filename terminating colon (which we could detect because it's in a different color).

Certain fullscreen apps use colors to separate different fields from each other, e.g. mc's bottom row (there are probably better real life examples).

Of course I'm sure this feature would have drawbacks, too. If nothing else then just the mere fact that it's an unusual behavior could be misleading.

Anyway, we could think about and experiment with this idea.