No, they aren't. They're the same color. It's the females who actually initiate the mating. They're the ones who go out and find the male and the male has to submit to them in Red Dragon society. Then, when the eggs are laid, it is whoever is the youngest that defends the nest while the eldest leaves, but has a lair close to the youngest of the pairing and watches over them.

If the female is the eldest and the male is the youngest, the female lays her eggs in the male's lair and leaves him to care for them until they hatched, but stays in a lair near by him to help defend him.

Females are actually more robust than males, they're more muscular and thicker than males, though both sexes are the same length and height.

But as for color, both are the same color and there isn't really any sexual dimorphism between the two. The true way of telling the difference is basically through pitch of voice, movement (females are a bit more graceful than males) and well, for the most obvious way–looking at their plumbing.

It has nothing to do with the blue tendrils in the female. That's a feature only present on Tanya's Red Dragon form.

So how about the scalespikes beginning from the tip of the males nose compared to hers beginning between the eyes instead then? :3
Also, the back of the male's chin have bigger spikes than hers, so is that something one can try and be on the look out for too or also only a trait for her as an individual?

It's only the chin, man. It's only the chin.

Hehe, okay then. ^_^

Yes. They are. the male is Jonathan and the female is Tanya