Incorrect behaviour git submodule

I created a template project. I called it Test. I created repo on github. I found the RestKit.xcodeproj file inside of the cloned RestKit project directory and draged it into the Project Navigator.

cd Test
git init
git submodule add git://github.com/RestKit/RestKit.git
git add .
git add -u
git commit -m "first commit"
git push

Push was OK.

My Test project:

I decided to check github's repo. I do git clone开发者_开发技巧. Clone was ok, but RestKit.xcodeproj appeared in red color.

Test project after cloning:

What is wrong ?

After clone you need to git submodule update -i