Hi @pthpndr
I think it’s probably due to the plugin using WordPress core color library and newer versions of WordPress no longer use that color library. Since a while back it’s using Iris http://automattic.github.io/Iris/
Having a quick look at the sourcecode of the plugin he does not seem to make sure iris or any other color js library is loaded at all.
So basically. Your issue is that there’s no color js library loaded with the plugin. To fix it you’d have to modify the plugin to include the library needed and probably rewrite the JS to work with that library instead.
