After settling, both layers are clear colourless liquids. How do you know which layer is the organ

In order to determine which layer is the organic layer or aqueous is to drip a drop of water into the mixture in the separator funnel. If the water drop dissolve as it hit the upper layer of a mixture then the bottom layer is organic. Also, if the upper layer is organic and the bottom is aqueous then the drop will travel through the upper liquid then dissolve when it reaches the bottom layer. Otherwise, if the upper layer is organic then the water drop will not dissolve and will sink to the bottom layer.  However, you can determine if the solution is (organic or aqueous) is by looking at the density of the water and the organic compound that mixed in the solution. If the density of the organic compound is less so it will be in the upper layer and water is lower layer and vice versa because compound with less density will float.