ActionScript 3.0 :: Set Selection Based On "selectedItem.label" Instead Of "selectedIndex"?

In a simplified version of my issue, I have a ComboBox called "cb". I can set its selectedIndex to 1 (corresponding with selectedItem.label of "Red") easily with:
 
cb.selectedIndex = 1
 
However, since "Red" may not always be at a selected index of 1, if another entry is placed before it in the list, I would MUCH rather base my code on selectedItem.label, since it will always be "Red."
 
How do I do this? I can at least trace the label's corresponding selection index with code like:
 
var frameSelect:Number = cb.selectedIndex;    trace(frameSelect)
 
Do I need some sort of loop function? Or is there a simpler way? Can I define a variable at the very start of my code that figures out  what the corresponding selection index of "Red" is on that particular  day? I basically need
 
var frameSelect:Number = cb.[Index of whatever goes with the label of "Red"]
 
If it useful to you, what I am doing (on a simplifed scale) is using a combo box to change the color of a movie clip. The user can click on "Blue" or "Yellow" or "Red" in the comb box, and the movie clip changes color. However, I also need a simple button that only has one outcome ("Red") where the user clicks on the button and thus sets the selected index of the combobox directly to "Red." Like I said, I can do this quite easily using the selectedIndex parameter, but this means I would have to manually update my button's code each time a new color option was added. Not remotely ideal, since the actual implementation has hundreds of colors in arrays and there will be lots of buttons creating arrangements from different comboboxes.(Say one combobox is Colors, one is Shapes, and one is Size. The end goal is to let the user experiment as much as they want through dropdowns, OR click a button like "Small green circle" to go directly to a particular outcome.)