This DIY is salt art in a bottle. This can be done in any glass container.
What You need.
1) Salt
2) water colour (paints)
3) test tube
4) glass container
5) empty container
6) water
7) gloves

Step 1: Let's Begin

Lay a paper on your working space. Take a empty container add salt an some paint, a very little water (drops of water) and it's ok if the salt is a little dry. Wear the gloves and Rub the paint to the salt and you will see the salt has taken the colour you want. Do the same with other colours. This we will use to make different colour layers.

Step 2: Pour Gently

Put the coloured salt in the test tube and pour the salt into the glass container seeing that it does not touch the walls of glass container. then add a few drops of water . as mine was small I added 2-3 drops. you will. see the quantity decrease and then you can add plain salt until the salt covers the water and you can see that there is no water. You can use your finger to level the salt before adding water. then repeat the process with other coloured salt and add water again. keep doing until filled. you can see the water in the picture. keep adding water for every layer and don't worry the colours won't mix until the below layer is covered fully with salt and there is no water