In case you dont feel confident navigating the site or feel like you pay me to do stuff so I should do it for you, here is the full Spirits tribal page on EDHREC
Effects that increase or reduce the cost to cast a spell don't affect that spell's mana value
The next card to be printed that altered a players maximum hand size was Cursed Rack in Antiquities , but instead of granting the controller of this artifact a limitless hand size, Cursed Rack reduced an opponents maximum hand size to four, meaning if they had more than four cards by the end of their turn, they must discard down to four during the cleanup phase
Not only do the original printings of these cards not lose much, but most of the commander printings actually increase from their low starting price while they are in print
So Thought-Knot Seer, Reality Smasher, and Matter Reshaper need specifically colorless mana, and Eldrazi Mimic needs colorless creatures