[Feature request] Split up vectors that have multiple parts so they can be colored individually

[Jnss98b]

Now I know that each icon is a single vector and many of them have more than just 2 or 3 parts so this is gonna take a lot of work but please consider it. I could help if you want me to.

Also, this might require a slight interface change because currently there is only a color picker for the background plus another one for the whole icon and a backend change to support choosing each part of the icon for coloring.