1. Since this is an introduction forum, welcome seeker9969.
2. Normally we prefer that you don't ask techie questions in the intro section. Your question would have been more appropriate under "Forms."
HOWEVER, that is not a dig because (a) you're new and we will cut you some serious slack and (b) with the turmoil caused by Jon having to change to a new forum base software ('cause the old one was out of date and not supported any more), none of us know where anything is, and (c) once it gets figured out, some moderator will probably move the thread for you anyway. So call that an FYI, not a poke.
3. I have never had trouble using "GotFocus" to change the color of a control. However, as you tried it on another database and it worked, that is a sign of possible corruption in the first DB. I can't point to such an article right now, but look up the Access "/DECOMPILE" command line option. Do that, then go in and compile your code. See if that fixes the miscreant DB.