Hi! It seems that your icon for the Darkness theme is 200x200px, so could you resize it? Don't worry, i'll include it anyway, but if it stays that big I'll need to use HTML for showing it in 100x100px and its quality might look worse that way, so I really recommend doing the actual resizing :D
It's taking me forever to make this post so if you happen to see this before I've made the post (which is a high likelihood) you'll have time to make the change :)