To theme for CCButtonBorder you will need to follow a few guidelines...

*This tweak takes advantage of being able to theme the CC Icon Background BUT there are wonky restrictions to doing this.  For now, this is out of our control...sorry. 😥

First:
Custom Images can be themed w/ Winterboard
  • BundleID: com.vxbakerxv.border

  • Label: CCButton_Border@3x.png

  • Up to: 180px-@3x / 120px-@2x / 60px-@1x

  • Create all three sizes above

Second, and this will take a little time. 😕
This doesn't theme like normal icons...
It's hard to explain but icons react to the background of the page 'behind' Control Center.  This 'reaction' creates a negative coloring effect through the BG icon image.  Vibrant colors and Black will permit this 'negative colorizing' to show through.

• Our first suggestion is:
- DO NOT use BLACK anywhere in the icon; a weird effect occurs with this.  Use Dark Gray instead!
- Even with shadows, use Dark Gray.
- Vibrant RED will also cause this effect

• Blending colors can create the same weird effect at the location where the two colors meet.

• Let transparency be your friend!  We've noticed that decreasing the opacity (sometimes all the way down to 25%) will give optimal viewing results.  For colored icons, 30-40% transparency works pretty well.

• Background color from the Springboard and Apps can affect how the icon looks.
• The DISABLED state of the toggle will darken your icon.
• The ENABLED state of the toggle will brighten your icon.
- Take this into consideration as the 'brightness' is ridiculously BRIGHT!


*** You're going to need to do a lot of trial and error but eventually you should have something that pleases you. ***

Enjoy and thanx for your support!!!

Sincerely,
     vXBAKERXv & thazsar