Change text color using javascript

I tried everything I can think of and just can't get this to work.In my "field1" validate tab I use this custom code

if(event.value > 0){event.target.textColor = color.blue;
}else if(event.value < 0){event.target.textColor = color.red;
}else if(event.value == 0){event.target.textColor = color.white;
}

field1 get it's value from another field. I want it to show if 0= white, if bigger then 0=blue, if lower then 0=red but the colors are mixed up,for example if number is 5 it should be blue but is white, 0 is red and -2 is blue but in field properties it shows correct color ( example in the field1 value is 5 it show white color but in properties it's blue) .If I enter value manually it doesn't change colors at all.