[FEATURE REQUEST] Custom accent colors

[7eventy7]

Summary: Allow users to customize the app's accent color, impacting all color-themed UI elements for a personalized and cohesive user experience.

Description: It would be great to have the option to change the accent color within Finamp. This customization could apply to:

• All colored text
• On/off sliders and toggle switches
• UI elements on the "Now Playing" screen (e.g., playback controls, progress bar, etc.)
• Any other color-themed components across the app interface

Overall this is a pretty low priority request, but I think it would help improve the UI a lot! With IOS 18 it would look really nice alongside tinted app icons as well :D

[Chaphasilor]

I agree this would be nice to have but has low priority.
I'd be happy to accept and help with a PR to add this, but I probably won't be adding this anytime soon...