There a quite a few potted plants in this cell. You can see on the left hand corner that a hint is given. It basically says that you need to count the number of potted plants from large to small. So:
Pink = XL = 1
Red = L = 2
Blue = M = 3
Yellow = S = 2
Green = XS = 1
Press the keypad and input 12321 and press OK. The bars will unlock and you can proceed to the next level.
