Describe the feature

I'd like the ability to change an individual frame and/or widget's texture bar to a specified texture

Describe the implementation

When editing the Target frame, I'd like the ability to set the texture for that specific frame
When editing the Target frame Power Bar widget, I'd like the ability to set the texture for that specific widget, etc.

Example:

I'd like to implement a reverse gradient texture to the Target healthbar as well as the target Power Bar widget for a more seamless look with my textures

When you say a reverse gradient texture, do you mean a separate texture entirely, or just the ability to rotate/reverse the texture?

For now I've made a snippet that can accomplish what you are after. Can't currently think of a good way to implement this into the UI.

https://github.com/Krealle/Cell_UnitFrames/blob/master/Snippets/CustomTextures.lua