Dropdown menu different colros

Hi,

I am trying to create a dropdown menu that has three different options colored with three different colors. The script i'm using works and the yes's are highlighted that color, except when I click anywhere else on the form the color disapears. I cannot seem to figure out how to fix this. I'm assuming there is a script to do that. Does anyone know how I can accomplish this.

I have a dropdown here. The customer wants One yes to be green, another to be red and the last to be no color. 

I'm using this script:

var f = event.target;
var fv = event.value;

if (fv == "Yes") {
f.fillColor = color.green;
}
else if (fv == "Yes ") {
f.fillColor = color.red;

So i see it works....yet the color dissapears eventually.