@fog , thanks to your little secret, it got me wondering whether Inkscape has a Find & Replace feature.
When working on my Kvantum theme, I’ve been using the same method as you, replacing colors manually in a text editor.
Even when I need to add CSS styling while working with icons, I stick to the text editor.
Turns out Inkscape does have a Find & Replace feature. Now I know. Thanks! 
Changing colors in SVGs isn’t really an issue when using a text editor. What’s more challenging for me is drawing vectors. I’m not great with numbers. Former math student here… with a very “E”xcellent result 
P.S. I didn’t want to spam the other thread, so I’m replying here 