Be careful relying on colour - as has been said many times before you have to cater for colour blind users.
The physical space and instructions might be enough (though a screen shot would help). You could also look at using bold text or perhaps a border to help differentiate this row from the others.
Are you getting feedback that people don't know what to do?
Based on the screen shot other things that spring to mind are:
- Increase the size of that row
- Use brighter colours (rather than just different colours)
- Use of tooltips perhaps.
You might find you have to do a combination of these things rather than there being one change that makes the difference.