This is one of my waterdrop photos.
The photo was taken on my old Nikon D5200 camera with a Sigma 150mm macro lens, 3 off-camera SB700 flashes and a bit of black paper for the background.
To get the colours in the water, I used some ordinary food colouring. I had a glass chopping board supported on tissue boxes as the surface with a flash with blue gel underneath, pointing upward. I put some drops of food colouring onto the chopping board and used a SplashArt water drop kit to make the drops. A flash at either side of the camera was used for the main illumination.