There is one bug: When "reload icons" button is pressed, the "Use Symbolic Icons" checkbox disappears when inkscape reloads, and requires switching to/from another preference section to restore that box.

Also, I recommend using the HSV colour picker as the default colour picker rather than RGB, because it's much easier to make adjustments to just the lightness of the icon without affecting the colour. I think we could do the user an additional favour of defaulting to a dark grey HSV(0,0,28) as the default for light themes, and light grey HSV(0,0,76) as default value for dark themes.

Thanks again to all who have made this possible. Very very cool, and helps to modernise the look of Inkscape substantially.

-C