As long as each camel you place is next to a same colored camel from a group that contains your rider, than you can make any formation you want with them.

...

You also cannot place a camel in an enclosed area (which are spaces that only a single caravan has access to).

Note that your last sentence is unnecessary since it's a consequence of the first requirement (that each camel you place is next to a same colored camel from a group that contains your rider).

I meant you cannot place a camel in an enclosed space even if it is the same color as your own caravan enclosing it. Which you wouldn't want to in most cases since you would be taking away points, but say you can't expand anymore with that caravan, you still can't put anymore camels in the enclosed space (like to try to have the most camels in that color).