Details for Kasina Meditation I've searched through the web and also Wikipedia regarding Kasina meditation and could not find detailed information. Can the meditation object be anything? (Say anything green or blue for those Kasina meditations?)

How does one concentrate on the object? Any thought or mental note (like green green? Earth?) Is the breath watched like in Anapanasati?
Here in this answer I am going to give some resources I found in the web and not going to copy and past anything here as the process is quite lengthy and detailed. You could learn about Kasina meditation from "Visuddhimagga (Path of purificaiton)". If your refer page 117 and onwards describe the details about "Earth kasióa". If you need a shorter version please refer here.

Further you could refer this page which describe how the create "Earth Kasina"(object) and describe how to do the meditation in details. Hope this helps.