After creating my variables, I’m unable to use them. There’s no dropdown for me to select from the variables when I’m going to select a color.
Usually, when you click on a color in the right-hand panel, you should see your variables available for selection in a dropdown menu, like in the image below.
Are you seeing a different menu entirely, or nothing at all? Also, is this issue happening in every document, or just a specific one?
To help us troubleshoot, please do as follows 
First, let’s see if the update resolves your issue. Try reinstalling the latest beta version using one of these installers: Windows, macOS, Linux
Once done, start Lunacy and go to Help > About > Check for beta updates, and then install any available beta updates.
See if the issue persists after doing this. If so, please specify the Lunacy version you’re currently using and your OS. You can also report it directly in Lunacy using Help > Report a problem, just don’t remove the log and device info while sending a message.