I've been working on making some interesting 'supernova' or 'hyperbeam' kinda looking backgrounds with Amberlight 2
I quite like them and it's quite satisfying fiddling with the various settings to get interesting interactions going on.
Here's one I did a moment ago, it's not super fancy but looks cool in it's own right.
This one is for a 2560x1440 resolution. You're free to use it as a background if you like.
I'm going to see if I can get some more interesting things happening and try a few different colour combinations.
Here's a bonus one I just made with also looks pretty cool.
Feel free to right click and save as to download.