Can we still push metadata onto the bitcoin blockchain and if yes, How do we do it and how fast will the ownership of a particular element get transferred from one person to another.
As mentioned by other posters, look into OMNI [1] (FKA Mastercoin) and XCP [2] (AKA Counterparty). I'm not sure how healthily maintained either project is though, as most tokens have moved onto the Ethereum blockchain.
The transfer speeds of colored coins should be the same as the transfer speed of regular bitcoins; at least so far I'm only aware of on-chain colored coin transactions on mainnet. Note that transaction size and thus transaction fees may differ from regular transactions.
[1]
https://www.omnilayer.org/[2]
https://counterparty.io/