Support for coloured underlines #7619
Description
System information:
fish, version 3.1.2
Running on Arch
Question:
With increasing support in terminals (Kitty, VTE, mintty, and iTerm2, and alacritty/alacritty#4660) for ANSI SGR parameter 58, underline colour. It would be awesome if fish would support it as well.
Personally was thinking that maybe it could be an optional parameter on the set_color -u flag so that it would be backwards compatible.
Example
set_color -u red
Edits:
2021-03-09: SGR parameter 53 should be 58 of course. Thanks @plgruener