I thought I saw stress stripes on my male honey last week and wrote it off. Then I reconsidered when he started glass surfing for a few days in a row (he was lonely because his partner had recently needed to be euthanized). So it's possible.
No, they don't. Change in colour is something to look out for with most fish however, usually a fade in colour.
The Honey Gourami usually show off that stripe when in breeding mood. They also typically show it when they are immature.