failed start up

I have a MacBook Pro, running Yosemite. Bought it in 2011. My notebook lost power because I forgot to plug it in while I was out during the day. No big deal, I plugged it in and tried to restart. It makes the startup chime, and then shows the loader screen with the Apple logo. Screen res seems to be of poor quality though, tiny vertical lines visible and grainy, and and also has a reddish hue instead of the neutral gray. The load bar will fill until about a third of the way, stop, get stuck, and then the loader and Apple logo go away entirely, leaving only the grey screen. Have tried safe restarting by pressing and holding shift with the same results. Tried letting it sit on the blank grey screen for a while with no change. Force shut down and let sit overnight, same results this morning. My fans aren't going crazy throughout this whole process, and I know that the computer is recognizing the charger, as the light was yellow, and now is green indicating full charge although the rest of the computer is non-responsive. I was running some programs when it lost battery to begin with, but nothing major. Just Chrome, with probably about seven tabs open. That's all. I've lost battery before while running Chrome and some graphic design programs and have never had this issue with startup.