Right. I have mine in hand. That side is white. The piece that mounts to the front of that (towards driver) is blue/green. The one in your picture looks white like mine is. So, I guess that was they way they came. I, too, figured the blue/green was to give the gauges a blue/green hue when the dash lights are on. Maybe the white is to give the two bulbs enough brightness? The console gauges use blue/green plastic for the same hue type reason?
Anyway, sorry I can't help w/ the color. It is a pretty odd one. Not like one would find that in the paint section of most stores. I wonder if a hobby shop would have something??? Yes, a auto paint store could/would match any color. But personally, I don't have the spray gun...