This thread is somewhat confusing..
But since it has the correct title I'll use it to post a link to the new Wallpaper in El Cap DP6 / PB4 anyway
full resolution download here:
El Capitan 2.jpg
As always since Mavericks, I went ahead and used this to make a generic color LCD icon, to show up in "About this Mac" and in System Preferences/Displays for non-Apple 3rd party devices. That's my TV via HDMI
Let me know if there's interest in this mod and I'll share a How to.