UINavigationBarAppearance and Navigation Bar TintColor

Is there a way to use UINavigationBarAppearance to change the color of icons in bar button items in a Navigation Bar (and change them between standardAppearance and scrollEdgeAppearance)? Previously this was handled with the tintColor, but this is now considered legacy and doesn't give you the flexibility between the different appearances. Accessing this property on UINavigationBar also doesn't seem to be working consistently for me now that accentColor has been introduced which makes this even more problematic.

At the moment, I seem to be only able to change the title and button text colors, but there's no way to change the image tints so you get some really bizarre combos — the texts will gain the color set in UINavigationBarAppearance but icons, including the back indicator, continue using the accentColor. In the worst case, they become impossible to see (white icons on white background).

If it is not possible to use UINavigationBarAppearance, is there another recommended way (or literally anything that works at all) to change the tint of images/symbols in bar button items between the scroll edge and standard appearances?

Thanks, friends! :D