cell coloring

I’m trying to set a School program for teachers only
Frankly speaking I don’t know how to make it in Excel. What I, trying to do?
1. Let’s have 3 teachers -Peter, Rick and Bill
2. When Peter takes first school hour, when name is written, the cell turns for example yellow. The same with other teachers but different color for each one.
3. When there is duplicate of names (in rows only), cells of duplicate names to turn into some other color. When duplicate is deleted, cell returns to original teacher’s color. I attach herewith a sample Excel file Sheet 1 shows green when there is duplicate, Sheet 2 shows what I would like to do.

So far I succeeded with conditional formatting to color duplicates (sheet 1) with formula
=COUNTIF ($F4:$L4;F4)>1 , turning cell green. And that’s it. I’m stuck.
Kindly ask you to help me.

school_pr2003.xlsschool_pr.xlsx

Look at Sheet 1(2), it should do what you want....

I'm afraid it works better/it's easier to do with Excel 2007 than with Excel 2003.

Thank you! It could be done also in 2007. If any changes should be done in 2007, please let me know. Thank you once again!

I would like to know if there some macro to be applied in Excel 2003 in order to fulfilled the task with more that 3 teachers? Say, mote than 5. Thanks in advance

Thanks for remark. I will but I do not see any link or contact tag for connecting. Sorry. I will have in mind in future. Thanks again