When picking colors, it’s very beneficial for an end user to compare the initial (previously-selected) color with the currently-selected color. This new Editors feature was added to the WPF and UWP color pickers in yesterday’s maintenance release.
Let’s see how this works with a ColorEditBox instance, our rich editor for color selection. Please excuse the GIF image dithering. The actual control has vibrant gradients.
The hue slider's inner circular area on the drop-down color picker shows the initial color value when the drop-down is opened. As the end user alters the selected color, the right half of the circle updates to show the newly-selected color, while the left half of the circle continues showing the initial color value. This allows the old and new values to be compared side-by-side.