It just so happens I am up late working to upgrade one of my apps on the Apple AppStore. I happened to need a color from a screen in another XCODE project. I proceeded to bring both projects up (so I had 2 XCODE instances running).
In Interface Builder one can double click on the Background Color of a Label to bring up the Color Selection Tool (shown below).
I was pleased to see that when I brought up the Color Selection tool from one project and toggled to the other XCODE 8.2.1 project then I could use that same color selection tool! It is shared and I never had to write down RGB values from one project, go to the 2nd project, retype them in that one, etc….
All I had to do was drag and drop the color (in this case pink – in the lower left corner) to the label in the other project!
As developers we do not always utilize every single tool we are given and so I decided to try out the eyedropper tool. It works on any window I have on the screen – not just in Interface Builder!
Having fun in XCODE 🙂