Not knowing what "Terminal Homebrew" is, I cannot directly address whether or not "Terminal Homebrew" allows customizing your standard Black, Red, Green, Yellow, Blue, Magenta, Cyan, White colors, However, I know you can customize the colors in Mac OS X Applications -> Utilities -> Terminal, and I can also do this with the iTerm or iTerm2 terminal emulators.
If changing your "Terminal Homebrew" settings back to default, corrected the problem, then it would either something you accidentally did to the "Terminal Homebrew" preferences, or the code is not stable, and it stepped on its own preferences for you 🙂 Not knowing anything about "Terminal Homebrew" I do not know how mature the code base is. I personally use iTerm and iTerm2 which has been around for a long time. I could most likely switch back to the Mac OS X Terminal app, as it has many of the iTerm/iTerm2 features I like these days, but old habits live on, so I continue to what I have been using.
If you like the color shades, but do not like what colors are associated with different file types, you can define your own LSCOLORS environment variable as per "man ls".
export LSCOLORS="AbadacbfexheagBedeAbAb"
This of couse would be best stored in your .bash_profile (or .bash_login (or .profile)). Since you said you changed the "Terminal Homebrew" to it defaults, I assume the color change was not related to LSCOLORS.
With respect to .bashrc. By default your home directory does not contain any shell initialization files for any flavor shell you like using (bash being the current Mac OS X default).
Bash initialization shell rules are spelled out in "man bash", but in brief, when you first create a terminal session (what looks like a login to the shell), bash will look for and execute the first one of the following found:
.bash_profile
.bash_login
.profile
Once you have an active Terminal session, if you create a subshell, bash will look for and execute the .bashrc initialization file.
If none of the above file exist bash will not complain.
If you want the .bashrc initialization script executed when you start a terminal session, you MUST source it from your .bash_profile (or .bash_login (or .profile)).
There are also global bash initialization files in /etc/ that may be executed, however, for a typical Mac users, it is best to leave them along, as they could be replaced during a system upgrade, or it is something easily forgotten when migrating to a new Mac, where as most people do remember to bring along the contents of their home directory.
With respect to being 67, many of the better contributers in these forums are not spring chickens either 😝