I'm assuming you shocked the pool hard with bleach?
If so, and it's been a few days at shock level, then probably the algae is dead. You will need to brush the sides and bottom of the pool, but if it's dead it should come off easily (live algae remains stuck to the surfaces). Color also changes from green to brown, although the entire pool can appear deep blue and cloudy. At this point, vacuuming, brushing, and filtration should clear the pool.
However, as said above, you need to test and monitor your chlorine levels so that you can be sure you've maintained shock levels of chlorine for enough time to kill the algae.
I had green algae when I started this season. I went up to about 30 ppm chlorine and maintained this for about 4 days. The first day, the pool started to look less green, but I still couldn't see the bottom. By day 2, I could see the bottom, but it was very murky and brownish/bluish. By the third day it was pretty clear, and by the 4th day it was perfect, and I started to let the chlorine levels drop to normal while brushing and vacuuming to get rid of all the dead algae.