I have Lightroom CC on my macbook and iMac, but the versions are different. I have just updated my iMac and now have Lightroom version 2015.7. My Macbook has version 2015.1.1 which has different controls for colour beneath the tone curve. HSL/Color?B&W which enables me to handle each colour independently, but the iMac version 2015.7 does not. I don't understand why my macbook has a more powerful person. AlfitzLightroom
The tone curve has two modes - click the little icon in the bottom right corner to toggle between them.
To see HSL/Color/B&W on your iMac, right click one of the panel headings in Develop and choose Adjustments.
You should update the Macbook to version to 2015.7 - on a Mac I'm guessing it's under Lightroom > Updates.
If that doesn't work, download from here: Keeping Lightroom Up-to-Date