I'm not an expert, but I haven't seen orange colored orange mint.

I have seen my spearmint leaves turn partially orange due to rust and disease.

There are organic soaps you can use to handle pest problems. I've used the suds from dawn dish detergent on leaves and then rinsed it off good. I'd try that, it won't hurt unless you go heavy on the soap and light on the suds. It's not organic but better than pest sprays.

good luck,