I find the contrast of the colors is much better when driving now. Things seem more bright/neon in a way and things actually seem to blend less for me. I was pleasantly surprised by the update.
However there are examples of the night mode driving directions having unintuitive colours: https://www.reddit.com/r/mildlyinfuriating/comments/17yv4qp/...
In this example the bright blue route (matching the directional arrow) is actually the optional path, the true path is the softer blue colour (as signalled by the turning direction at the top of the screen.)