I think given time there will be something, however I cannot see if it will happen as it uses the S-Class UI which isnt a theme based UI (unlike the old viewty, which unfortunately you had to hack to install custom themes). All we can do is wait but I wouldn't get your hopes up too much.
However if a developer does read this, an idea could be to try to remove the S-Class part of the system and create a custom one that is customisable
