One of Substance users has switched from version 3.3 to the 4.* line, and is now missing his favorite Streetlights skin. Indeed, it has been removed about a year ago in version 4.0. This specific skin was never marked as officially supported, and the reason was simple – the old theming layer was not powerful enough to support a skin that mixes dark and bright colors.

It is difficult to design a pleasant skin that combines dark colors for overall controls and bright colors for active controls (selected, rolled over, pressed, armed). It is more difficult to implement such a skin in a programmatic way, and even more so to properly support animations. With usual bright colors you only need to animate the background fill while the foreground color stays the same (usually black). The dark-bright switch requires animating both foreground and background colors. Also, there are many corner cases that reveal themselves only with this specific combination. For example, using the same bright colors for both inner fill and outer border of a selected button results in a very fuzzy appearance. It is much better to use dark colors for painting borders of brightly-filled buttons.

As i have already mentioned, the new version of Substance (currently under development) as much more powerful theming layer. Now it is possible to bring Streelights back to life, this time with much better and consistent visuals. Here is a thumbnail of the test application running under Streetlights (click to see full size):

You’re more than welcome to read the code behind the Streetlights skin. It is available as part of the Extras pack.