After Effects version 13.5 has blue highlight colors, yet your screenshot shows a yellow highlight. That's odd. Are you sure those are both your screenshots?
You should update your OS. In 10.10.4, Apple fixed some pretty major bugs affecting AE.
I´m a Creative Cloud-user since 2 years and never had such bad issues with AE since I updated it to CC 2015. With CC everything was ok, but I´m forced to use CC 2015 now because of teamwork. Even if I´m not using any effects I´m not able to work with it longer than 10 minutes. I get the same "unable to allocate...."-message like the user above or the one I added as a screenshot - the memory is totally rising up in a few minutes (screenshots before havong started AE and while using AE)....I have a macbook pro (16GB 1600 MHz DDR3 / 2.3 GHz Core i7). The space-button does not work properly with the preview and there are audio issues, but these are the problems that are not so important as the others.
Im encoutering the exact same problem . Heres link to my discussion : Re: "unable to allocate memory after effects CC 2015" Mac Pro bug fix?
I filed a report and no word. Im hoping Adobe's silence is due to them working away on a crucial update.
ps - My OSX is up to date and i still cant use AE ....
ill let you guys know if i here anything back.