Why are there some blue folders in my Xcode project?

When I import my project from Github, I have two folders which appear in Xcode with a blue color, but all the other folders are yellow. What's going on?

Solution 1:

Blue is used to represent a "Folder Reference".

A clear description of what these are and when to use them comes from http://struct.ca/2010/xcode-folder-references/

There are two types of folders in Xcode: groups and folder references. You can use groups to organize files in your project without affecting their structure on the actual file system. This is great for code, because you’re only going to be working with your code in Xcode. On the other hand, groups aren’t very good for resource files.

On any reasonably complicated project, you’ll usually be dealing with dozens – if not hundreds – of asset files, and those assets will need to be modified and manipulated from outside of Xcode, either by you or a designer. Putting all of your resource files in one flat folder is a recipe for disaster. This is where folder references come in. They allow you to organize your files into folders on your file system and keep that same folder structure in Xcode.