Vuetify multiple themes

I was reading the Vuetify documentation and it seems you can create two themes like so:

const vuetify = new Vuetify({
  theme: {
    themes: {
      light: {
        primary: colors.purple,
        secondary: colors.grey.darken1,
      },
      dark: {
        primary: colors.blue.lighten3,
      },
    },
  },
})

And then is possible to use it by: this.$vuetify.theme.dark = true

Is it possible to add another theme? Kind of like this:

const vuetify = new Vuetify({
  theme: {
    themes: {
      light: {
        primary: colors.purple,
        secondary: colors.grey.darken1,
      },
      dark: {
        primary: colors.blue.lighten3,
      },
      anotherTheme: {
        primary: colors.grey,
        secondary: colors.black,
      }
    },
  },
})

And if it is how can I change to it programmatically?