To Make a Rain Cloud in a Jar, You Need:

• A large jar
• Shaving cream (make sure it’s not the gel kind)
• Gel food coloring or washable watercolors
• Pipettes or Droppers
• A small cup
• Water

Instructions:

1. In one small cup mix the food coloring and water. Do this for each color you want. 
2. Fill the large jar with water until it is about ¾ full.
3. Place a pipette or a dropper in each cup of colored water.
4. Spray a bunch of shaving cream in the jar until there is just a little bit above the jar. 
5. Pick up some colored water and drop it on the top of the shaving cream. Repeat a few more times.

Cites:

https://funlearningforkids.com/rain-cloud-jar-science-experiment/

https://thestemlaboratory.com/rain-cloud-jar/