We used light coloured sand since we have have black ants in our backyard.
Feed your ants once a day and water it every other day. A cottonball soaked in water and sprinkled around and then dropped in works well for this. They eat: bread, sugar water, fruit, and a variety of other things. For the most part, think sweet and your ants will be happy. They also eat dead bugs so that's an option as well.
OH! To help keep them in the jar you can put a paste of baking powder and rubbing alcohol around the top of the jar. They don't like going past that barrier which makes feeding and watering them much easier. :)
If putting a lid on your colony (just a good helpful backup) put lots of tiny holes in it or use some type of very small screening.