Chromatic Orrery seems ok for decks that can reliably cheat it out ( looking at you Arcum Dagson ) or ones that treat it as a combo piece. While Grim Monoliths of the World achieve infinite colorless mana for cheaper they do need an outlet for it. With this you're good with the same untap
shenanigans as long as you have some permanent with color on the field. Then you just create infinite mana and draw your deck with the draw ability. So basically imo it can be worth it in certain decks or with certain strategies but auto include? Nah man.
Edit: looks like Kotka swooped in as I was typing
I'll be a parrot then!