Javascript with "OR" statement - PDF Form

I need some help as I am new at this:  I am setting up a fillable form but I have been asked to create the text boxes change colors if the numbers entered are incorrect.  I have the code, but it is for only set of numbers for each color, Red, Yellow and Green.  I need to add a second set of numbers for Yellow and Red and I am having issues, please help if you can.  Here is the code I have so far:

var v = Number(event.value);if (v>=720 && v<=880) {event.target.fillColor = color.green;}else if (v>881 && v<=920){event.target.fillColor = color.yellow;}else if (v>920 && v<=2000) {event.target.fillColor = color.red;}else event.target.fillColor = color.white;

Thanks