With Vizier of the Menagerie, "you may spend mana as though it were mana of any type to cast creature spells." Does that allow you to call out the colors you need to cast Converge creatures like Skyrider Elf or Woodland Wanderer? Thanks!
Vizier of the Menagerie lets you spend mana to cast creature spells as though it were any type (color or colorless), yes, but spending mana “as though” it were some color only matters for paying costs and isn’t considered for effects like converge. Skyrider Elf knows what colors of mana were actually spent to cast it, and the converge ability will only have it enter the battlefield with that number of counters.
For example, when you spend two green mana and three colorless mana to cast Skyrider Elf spending it as though it were WUBRG instead of CCCGG with Vizier of Menagerie, Skyrider Elf will enter the battlefield with only one +1/+1 counter on it since only one color of mana was actually spent to cast it.