Just like this:
To do that, just add the following css in the “advanced customization” section of your editor:
i.icon.ion-ios-arrow-back, span.default-title.ng-binding, span.nav-bar-title.ng-binding, button.button.button-clear.header-item {
color: #887f77 !important;
text-shadow: 0 1px 1px rgba(255, 255, 255, 0.7);
}
Obviously you have to change the color code “#887f77” by your own. To get the best result, choose a color darker than your background.