I got an image on terminal from the output of homebrew package manager

I think it depends on how many tools/libraries you need to install.

If just git then use Xcode 4 which you will need for any port package. If you are doing pure HTML/Javascripy/CSS then the git installer will work.

For python and perl and similar interpreters the the language install tools can be used unless there are complex C/C++ libraries

If only a few others then build into /usr/local

However if you have several things to install or there are complex dependencies then I would use a ports package like Fink, macports or homebrew (which is best is debatable and should be a separate discussion)

The culprit probably is line 88 in your prompt.sh:

trap 'echo -ne "\033[00m"' DEBUG

This will output an ANSI escape code to reset the colors and style before the output of every command.

From examining your bash script, this line seems to be unnecessary, because you are resetting the formatting at the end of your prompt here on line 76:

PS1="$status_style"'$fill \t\n'"$BY\$(__name_and_server)$Y\w$G\$(__git_prompt)$RESET$ "

I suggest you just remove line 88 and try it like that.

Somewhat unrelated to this problem, but I also suggest editing line 73 to the following:

local RESET="\[\033[0m\]"

This way you are truly resetting the ANSI styling, whereas before you were setting it to white.