The top nav bar background appears to be the same as the module link hover colour. Making it darker means that the hover colours for the side modules (such as tags) are then unreadable. I've tried to compromise on a mid-purple for now, and will submit a support request. Ideally I think I'd make that the same colour as the entry title background, and then keep the hover colour the same as the normal hover colour.

Is dark purple better than dark blue for the entry titles? I've done an updated version.