From what I can see the plug-in seems strictly developed for a specific version of AEM, I conclude that because there is a version of the same plugin for each different AEM version (6.4,6.3,6,2, etc). Are you using a proper version of this plugin that matches your AEM instance? (Please note that the plugin does not say anything about Service Packs in 6.5 so that may be a reason why it is not working).
That being said, the issue shows that there is a path that is built manually and is not properly formed ('/apps/abc/components/v2/plugins/rte-color-picker/color-picker-popover/undefined'), something is returning "undefined" and being appended to your plug-in path, the best way to solve this is to debug the JS and check where this can be failing.