I am looking for more potion colours, so I made this image. The top row are bottle overlays and the bottom row is the liquid shape. To use it, take a bottom shape, tint it the colour of your liking (try not to use colours close to pure white or pure black) and put the corresponding bottle over it.

Here is a little demo:
 
As you can see, I made grey, deep purple, brown, teal, and lime potions, which are not present in the original image.

If you want to use my overlay and shape method/image, you don't need to credit me, do just as if you are using Bonsaiheldin's original image.