"Matching" Tach and Oil/H2o Gages
If that's the same color as what I used (voltmeter) for my ammeter / voltmeter conversion, it IS orange, but perhaps a lot darker shade and of course it would depend on how much yours have faded over the years
(This was not my idea, this thread is where I GOT the idea for mine, and used the same gauge)
http://www.forabodiesonly.com/mopar/showthread.php?t=119480