Theming: Level-based colors

[m0ksem]

[asvae]

@xx13 can you provide more data on this?

[m0ksem]

The idea here is to have v-level="2" directive or prop. This will make it easier to work with background. For example, for high level we have light background, for low level it will darken backgrounds.

I think this has super low priority for now.