A while back I happened to see Evan's minimalist Gmail notifier. One thing that struck me about it was that he not only base64 encoded his icon data, but that he split them into header, palette and footer sections. By swapping out the palettes, he could easily create active and inactive versions of the same icon.
Back in the days when most games were written for 8-bit displays, color palette animation was a common technique for simulating change without having to actually push new pixels to the screen. Out of sheer curiosity, I tried to replicate the same effect in a browser, using
The main gotcha that I encountered is that using PNGs isn't really an option. All chunks in a PNG image (including the
I'm not sure if this technique has any real world value (even ignoring MSIE's lack of support for
data: URLs), but it's still fun to see old school techniques such as this resurrected.