CDock Customizes the Background and Color of Your Mac’s Dock
Apple doesn’t offer you many options for customizing your dock in System Preferences. The free cDock app lets you customize the colors and backgrounds to your liking.
cDock lets you change anything in the Dock. It comes with pre-installed color themes so you don’t leave your Mac transparent by default (I love the blue background myself). How-To Geek explains how to add a bezel around the dock and more – which comes in handy if you’re remotely controlling another computer and don’t know which dock you’re using. Follow the link to learn about all of your customization options.
cDock | SourceForge via How-To Geek