OK - there's two ways to handle this...
1) If you have a test light, put the high beams on and see which wire's live (the black one is usually earth - but that can be quickly verified with a voltmeter. Also, a voltmeter can sub for the test light, if that's all you have. I got rid of my test light years ago - limited information available.)
2) You tell us what year you've got - automotive wiring systems are never static. We really need to know more - while you've given us the wire colours, that doesn't tell us what you've got, and how are we to know if the wiring's been changed? Even for the simple questions, a line like this:
1989XJ/4.0/AW4/NP231/D30/D35 - 3.55
will work wonders. Read that line as "1989 Cherokee, 4.0 inline six, AW4 4-speed automatic transmission, NP231 transfer case, Dana 30 front, Dana 35 rear, geared at 3.55:1" It's not really necessary to specify XJ or MJ past 1992 (the last year the MJ was available,) and if you don't know your transmission or transfer case, you can say "Auto" or "Manual" in that place, and if you don't know the transfer case, you can sort it out quickly by checking for the presence of a "4WD Full-Time" setting - the NP242 has it, the NP231 does not.
It's amazing how much help a line like that can be when we're trying to answer you.
Remember, I'm not trying to be a wiseass - I'd really like to help! Problem is, I need a little more information to figure it out (I've got a dozen FSM's right here, but I'm not about to go through wiring diagrams in all of them to find out which headlights are wired BLK : VIO : RED/ORG. It would take time I'd prefer to spend on other things. Granted, I'd probably have figured it out by now, but I think helping you form good habits when asking questions is a more productive use of my time...)
5-90