I'm referring to this indicator:

There are no options to change the icon theme for the indicator on the panel, and the default color theme looks ugly on Radiance theme. Are there options I don't know about or could settings be added?
I'm referring to this indicator:

There are no options to change the icon theme for the indicator on the panel, and the default color theme looks ugly on Radiance theme. Are there options I don't know about or could settings be added?
Found a solution to manually change the icon after some file searching.
First download this black icon I created using GIMP (same icon as the official application's, but with inverted colors):

Open Nautilus File Manager as root. I did it graphically because I'm not familiar with much of the terminal. I used this command in Terminal.
gksu nautilus
Go to File System and navigate to:
/usr/share/notify-osd/icons/gnome/scalable/status/notification-display-brightness-full.svg
Copy the file's name, and then delete the .svg file.
Replace it with the icon I provided above and give it the same name as the previous file (paste what you copied in the above step).
The icon should change, and look great in Radiance theme. If you want to change back, you can invert the colors of the icon I gave using GIMP and export it as a new image, and then do the same process above using the new image.
Sorry if anyone can do this easier in the terminal and I just showed a harder way, I only discovered Linux a month ago and still am not familiar with command line lingo.