Just good ol' draw.io desktop app: https://github.com/jgraph/drawio-desktop

Comments below already figured out the rotate-hue trick :)

Styling inside the SVG is possible... if the SVG is inline, and not in an `<img>` tag. Also, it would be really hard to target which elements to style, as draw.io does not really give you classes for each color family.

Oh also, I have a whole .drawio => .pdf => .svg => optimized .svg pipeline so you can just save the .svg and not worry about having the fonts. (But also the svg no longer contains the text itself — it's a trade-off).