Changing wireframe colour

When I enter wireframe mode, all the segments appear in a light blue colour against a grey background. This is useless for me because there is no contrast.

However, if I zoomall the way underneath the sim below "sea level", the wireframes have have a darkened appearence; which is what I need.

Is there a way to change the colour of the segments in wireframe mode?

Which blue do you mean, the regular one or in edit mode? Some of the lines use the sky color, and World->Environment Settings->Midnight will improve those. I'm guessing that's the part you are having trouble with because of the underwater difference…