This can be randomly acquired from the paid content crates in the store.
You can use the paint by touching the 'spray icon' on the top left corner of the screen during the match.

[Applying/detaching/changing paints]
1) Applying
- Drag the paint you wish to apply and place it in an empty slot
2) Detaching
- Select the applied paint from your slot and drag it out
3) Chaning
- Select the applied paint from your slot and drag it out, place another paint in

※ NOTE ※
- Paints can be sprayed on land, buildings and cars
- There is a cool down time of 6 seconds
- If you spray the paint twice, the previous one will disappear
- You can also use them in the Training grounds and they will be deducted