Okay, so I did a custom build (build-config.js can be posted on request..), and included the plugin 'enhancedcolorbutton'. Downloaded CKEditor as a minified, ready-for-production package. (Not sources.)
When loading CKEditor onto the page, it's trying to run back and grab plugins/enhancedcolorbutton/plugin.js. This is returning a 404, because there is no plugin.js in the plugin folder on the minimized download. (The only file present is css\content.css.)
If I go and download the plugin manually, and copy it's contents to the ckeditor install folder (note that the downloaded plugin has other folders, too - icons and lang), I get the following errors:
The resource name "enhancedcolorbutton" is already registered. and
TypeError: g is null
So, is something wrong on their build script (guessing..) and is there a way to correct it?
Please have a look at https://ckeditor.com/cke4/addon/enhancedcolorbuttton. This plugin is some third-party add-on which was created for CKEditor 4.5.8 so we don't even know if it still works with 4.8.0 (author should check it against every new editor release).
Please download the 4.8.0 build and then add this plugin manually. While trying to run the editor, please see what gets returned in console. Please also check comment under the plugin - one person says there is an error ttt instead of tt so some renaming of might be needed (perhaps even inside the source files).