To complete the quest, it is necessary to prepare together three potions - orange, purple and green:
The purple potion is a mixture of two colors - blue and red. As you can see in the picture below, the pre-determined colored potion is blue potion. To be able to prepare the purple potion, it is necessary to add a red potion to the corresponding place. After the red potion is added, please, push the piston according to the picture:
After you push the piston, the pre-determined blue potion and the additional red potion will mix to create the desired purple potion.
Then it is necessary to repeat the procedure with the apparatus on the right side. In this case, you need to prepare a green potion. Actually, green color is a mixture of yellow and blue color. As you can see in the picture below, the pre-determined potion at the top of the apparatus is the yellow potion. To be able to prepare the target (green) potion, we need to add blue potion to the apparatus. This can be done by dragging the blue potion to the corresponding place according to this picture:
After the blue potion is added, please, push the piston according to the picture. This will result in mixing the two colored potions (pre-determined yellow and additional blue) into the desired green potion.
After these two procedures are successfully completed (the flasks are both filled with the desired colors), it is necessary to drag them to the corresponding places according to this picture:
Credits for this walkthrough go to Romi 🙂