Feature proposal/request: input line highlighting

[Thomas Wolff]

Hi,
as opposed to having a fancy colored prompt, I would like to be able to set up coloring of the whole bash command input line (but not the following command output). This could be achieved by adding a variable like "AFTERPROMPT_COMMAND" which is executed after a prompt line is completed (or "PS9" which is output after a prompt line is completed).
It could even be a nice idea to configure this behavior separately for bash and readline, so the users have a choice whether to color just command input, readline-handled program input, or both.
I would appreciate this feature, and maybe even supply a patch if I had a clue where to hook it in...
Thanks and kind regards,
Thomas