Plone.app.widgets -- how to use shipped textcolor plugin? (1.8.0 on Plone 4.3)

I am testing plone.app.widgets 1.8.0 on a Plone 4.3 site, and cannot figure out how to enable the shipped (but not configured/enabled) textcolor plugin. My interest here is equally (but less urgently) applicable to TinyMCE 4 as shippedin Plone 5.

I have tried modifying TinyMCE.defaults.tiny.toolbar and TinyMCE.defaults.tiny.plugins, but without success.

Sean