Select a bottle, then its destination. The entire top layer flows until the receiving bottle fills. Pour only onto the same color or into an empty bottle. Gather ALL of each color into ONE bottle; headroom is allowed. Small bottles are useful temporary buffers. Undo and restart are always available in the site toolbar.
Every puzzle has a verified solution. One move pours the whole available top layer, not just one unit. Hints search from your current position; use Undo if you reach a dead end. No time limits, lives or paid extra bottles.