how do you work with water?

I'm a bit confused when it comes to working with all several containers of water. I am a newbie (no gigs yet, just practicing) and currently use one container of water.

My (incorrect) routine:
1. Wet round brush, tap excess water on paper towel.
2. Load white paint.
3. Paint design.
4. Swirl brush in water, tap & drag on paper towel (repeat until no colors show up on paper towel)
5. Wet round brush, tap excess water on paper towel.
6. Load pink paint.
7. Repeat.

What is the correct way to do this?
What would the procedure be if you were using the same brush for different colors?
I've seen the use of 4 containers of water (one for black, one for white, one for colors, and one with clean water).
Is that why it's recommended to have 3 of each round brush?

I can't seem to find anything online on how to go about this. Most face painting design tutorials do this part off camera.

Help!

the process many people use is basically as follows, canadian face painters will tell you they must follow regulations to disinfect equipment between faces -

1st cup of water, may have a drop of soap or brush cleaner and a scrubby in the bottom, to get most paint out of brush,

2nd cup of plain water to rinse out remaining paint and painty water, blot brush dry,

3rd container of 70% rubbing alcohol to disinfect brush, blot and let evaporate until dry, keep container closed between rinses so alcohol doesn't evaporate,

or 3rd cup of plain water for extra clean rinse.

dump rinse water into collection container (or discreetly on ground if outside) when it begins to look muddy.

although i use multiple cups of water for rinsing, and discard before it gets too dark, i don't rinse between each face as long as the child or person doesn't look sick, or have a runny nose, cut, rash, etc.

face paints have antimicrobial ingredients and most people have normal immune systems. (you guys that paint at hospitals, don't jump down my throat )

i have sets of different size brushes for similar colors - ex. a couple sm rounds, lg rounds, and flats that are interchangeable between red, orange, & pink, and another set for blue, purple, & green. also a couple for white, and for black.

i rinse after several faces, or if i need to change to a different color (i am not in canada). i think some other face painters may also do this.

My brushes are dry and clean - I add water to my cakes with a squeeze bottle, just a couple drops at a time. Water is ALWAYS clean that is added to the make-up!

I use a three compartment water tub for cleaning and rinsing. Brushes are washed with soap, rinsed twice then saturated in 70% isopropyl alcohol, and left to air dry before being used again.

When the wash compartment in the tub is murky, it is dumped into my used sponge bucket, and fresh water added.

I've got photos of my tub and set-up here https://shannonfennell.wordpress.com/whats-in-my-face-painting-kit/

Thank you jlirie and Shannon, I think I understand now!