Tput

The Termcap DB is a library/db that abstracts control codes to manipulate a terminal.
The tput command can interact with it from shellscript.

Documentation

man tput

https://man.archlinux.org/man/core/ncurses/tput.1.en

Console Info

tput lines  # height of terminal in chars
tput cols   # width of terminal in chars

Text Formatting

# colour
tput setaf 1  # set foreground colour to 1/255 (red)
tput setab 1  # set foreground colour to 1/255 (red)

# weight
tput bold  # bold
tput smul  # underline

# reset
tput sgr0     # reset formatting

Help Menu Colouring

I wrote and use this a lot.

setup_colours() {
    if [ $(tput colors) -gt 8 ] ; then
        C=$(tput setaf 6)  # code
        H=$(tput setaf 3)  # heading
        E=$(tput setaf 1)  # error
        B=$(tput bold)     # bold
        R=$(tput sgr0)     # reset
    else
        C=$(tput sgr0)
        H=$(tput sgr0)
        E=$(tput sgr0)
        B=$(tput sgr0)
        R=$(tput sgr0)
    fi
}