Ugh, before we've refactored them into eSVG. I'm just so busy! š
OK so note that some past contributor accidentally put guides in Y axis up instead of down, it's using the wrong coordinate system.
Previous versions of Inkscape only used integer RGB32 notation for colors. I fixed this in 1.3 to allow for any css color format. So at least that won't be bloody weird.
You're invited to eSVG discussions if you do this, be warned š