Overview
RCA Themer is a free Helix-oriented CSS tool with two separate surfaces that people confuse on purpose when they want confusion. The retail system plugin plg_system_rca_themer puts a floating Styles panel on your live Joomla frontend for Super Users so you can click elements, inspect matched rules, edit declarations, export dirty CSS, and optionally write surgically to an allowlisted custom.css file. The separate free hosted lab at https://recreatinganew.com/themer lets you design against Helix and SP Page Builder fixture chrome in the browser and paste the export yourself with zero install risk on production. Documented retail plugin line for this manual is 1.1.6 on the free feed at https://recreatinganew.com.
Path A versus Path B
Path A is the plugin on your site: install the ZIP, enable System - RCA Themer, open the panel on the live frontend as Super User. Path B is the hosted lab: open https://recreatinganew.com/themer, tune colors and tokens against fixtures, export CSS, paste into your template yourself. Both paths are free. Only Path A can touch your live filesystem when you deliberately enable live write.
What the ZIP installs
The retail ZIP installs System - RCA Themer only. The hosted lab is not inside the ZIP and nothing from the lab installs on your server when you export CSS.
What Themer is not
Themer is not a replacement for Helix Template Options color pickers; it complements them. It will not rewrite third-party CDN stylesheets. It is not permission to edit Helix-compiled template.css for durable brand work, because Helix updates wipe compiled sheets and you will blame the wrong product. Put lasting overrides in custom.css, which Helix loads last.
Who should keep reading
Keep reading if you run Helix Ultimate, you keep brand overrides in custom.css, and you want a live inspector on real pages or a fixture lab before paste. Skip Themer if you expect it to patch CDN CSS or if you are not a Super User and expected guests to see the Styles panel on the public site.
Where to go next
Use Quick start for Path A export-only on a Helix site. Use Frontend for hosted lab workflow at https://recreatinganew.com/themer. Use Configuration before you turn on live write on production.