So far, we’ve seen quite a number of style setting commands and tools in Inkscape, each with its own approach and capabilities. However, each of them has some downside. In particular, the Fill and Stroke dialog and the selected style indicator cannot edit many different colors without unifying them. The Tweak tool, on the other hand, which can adjust multiple colors at once, requires you to actually paint on canvas and can therefore be slow and imprecise for some tasks.
As a workaround, a group of extensions in the Color submenu of the Extensions menu allows you to adjust all colors of a selection at once. These commands affect both fill and stroke colors, including colors of gradient stops, but excluding bitmaps or patterns. They include:
A full set of HSL adjustments (increasing and decreasing hue, saturation, or lightness by 5 percent)
Brighter and Darker (adjust brightness up or down by 10 percent)
Desaturate extension (set HSL saturation to zero)
Grayscale (equalize the three RGB channels; the result is largely similar but different from that of Desaturate)
Negative (for example, convert black to white, yellow to blue, and so on)
Commands for removing or swapping the Red, Green, and Blue channels
A Custom command which allows you to set your own formulas for modifying the color channels, using the values of other channels if necessary
Yet another way to change colors of objects is by using SVG filter effects (Chapter 17), in particular the preset filters from the Filters ▸ Color submenu, or any others using the Color Matrix primitive. Compared to extensions, SVG filters are better in that they are nondestructive (the original look and color of an object is preserved and can be restored simply by removing the effect) and work on everything, including bitmaps and patterns. However, filters slow down rendering, and custom filters may be cumbersome to create.